# i-80 Gold Announces Positive Feasibility Study and Initial Mineral Reserves for Granite Creek Underground; After-Tax NPV\(5%\) of $118 Million at $2,750/oz Au Increasing to $598 Million at $4,500/oz Au

Canonical Atlas analysis: https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a

Original source: https://orestocks.com/company/IAU.TO/press-releases/5816897245739500

Publisher: orestocks

Original announcement: 2026-09-21T22:48:00.000Z

Analysis by Minestarters Atlas

Atlas analysis published: 2026-09-21T23:41:57.139Z

Atlas analysis updated: 2026-09-21T23:41:57.139Z

- Company: i-80 Gold Corp.

- Ticker: IAU

- Exchange: Unavailable

- Region: Nevada, USA

- Primary commodity: Gold

- Secondary commodities: None reported

- Document categories: Resource update, Production, Metallurgy

- Extracted: 2026-09-21 23:41:57 UTC

Narrative sentiment: 0.90 · Bullish

## Minestarters Atlas summary

i-80 Gold announced a positive Feasibility Study for its Granite Creek Underground gold project in northern Nevada, establishing initial Proven and Probable Mineral Reserves of 2.20 Mt grading 7.87 g/t Au containing 556,500 oz Au. Measured and Indicated Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au. The study projects an after-tax NPV\(5%\) of $118 million at a base case gold price of $2,750/oz, with an 8.5-year mine life and average annual gold production of 75,000 oz from 2028-2032, supported by an optimized processing strategy at the company's Lone Tree plant.

Reasoning: The Feasibility Study for Granite Creek Underground outlines robust economics, establishes initial Proven and Probable Mineral Reserves, and significantly increases Measured and Indicated Mineral Resources, demonstrating strong project advancement and future production potential, despite the refractory nature of the ore.

- Positive factor: Initial Proven and Probable Mineral Reserves established, providing a robust foundation for future production.

- Positive factor: Significant increase \(229%\) in Measured and Indicated Mineral Resources, indicating improved geological confidence and potential for further conversion.

- Positive factor: Conversion of Inferred resources to higher confidence categories \(Measured and Indicated\) demonstrates successful infill drilling.

- Positive factor: Positive project economics outlined in the Feasibility Study, with a substantial after-tax NPV at base case gold prices.

- Positive factor: Optimized processing strategy utilizing the company's own Lone Tree plant is expected to reduce future operating costs.

- Positive factor: Project is fully permitted and already ramping up production, indicating advanced stage of development.

- Positive factor: Ongoing exploration programs suggest potential for further resource growth and mine life extension.

- Negative factor: Historical drill results for the CX Zone, mentioned as a prospective target, lack QA/QC data, reducing confidence in those specific intercepts.

- Negative factor: The ore is predominantly refractory, requiring an oxidation process \(POX\), which can be capital and energy intensive.

- Negative factor: All-in sustaining costs are relatively high at $1,915/oz Au for the steady-state period, which could impact profitability at lower gold prices.

Low confidence — this extraction should be reviewed alongside the original source.

Facts used in scoring: 26

## Classification and evidence

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: The document announces 'Initial Proven and Probable Mineral Reserves of 2.20 million tonnes... containing 556,500 ounces... of gold'.

Evidence · text

> Initial Proven and Probable Mineral Reserves of 2.20 million tonnes \("Mt"\) grading 7.87 grams per tonne \("g/t"\) gold \("Au"\) containing 556,500 ounces \("oz"\) of gold \("Au"\).

**Probable Reserve**

Polarity: positive

Definition: Indicated Resource with demonstrated economic viability after applying modifying factors.

Why it applies: The document announces 'Initial Proven and Probable Mineral Reserves of 2.20 million tonnes... containing 556,500 ounces... of gold'.

Evidence · text

> Initial Proven and Probable Mineral Reserves of 2.20 million tonnes \("Mt"\) grading 7.87 grams per tonne \("g/t"\) gold \("Au"\) containing 556,500 ounces \("oz"\) of gold \("Au"\).

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: The document states 'Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au'.

Evidence · text

> Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: The document states 'Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au'.

Evidence · text

> Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au

**Category Upgrade**

Polarity: positive

Definition: Resource confidence improved — Inferred upgraded to Indicated, or Indicated to Measured. De-risking signal.

Why it applies: Measured and Indicated underground Mineral Resources increased by 229% while Inferred Mineral Resources decreased by 38% as the infill program converted a portion of Inferred Mineral Resources into higher classification categories.

Evidence · text

> Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au, compared to the PEA\(1\); Inferred Mineral Resources decreased by 38% to 0.89 Mt grading 7.06 g/t Au containing 202,800 oz Au as the infill program converted a portion of Inferred Mineral Resources into the higher classification categories.

**Contained Metal Growth**

Polarity: positive

Definition: True scale improvement — contained metal ounces/tonnes increased vs prior, accounting for both tonnage and grade changes.

Why it applies: The document states that 'approximately 65,000 ounces have been added to mineral inventory' after accounting for mining depletion.

Evidence · text

> approximately 65,000 ounces have been added to mineral inventory

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: The technical information has been reviewed and approved by Benjamin Parsons \(MAusIMM CP\) for Mineral Resources and Anton Chan \(P.Eng., MMSAQP\) for Mineral Reserves, both Qualified Persons.

Evidence · text

> prepared under the supervision of, and has been reviewed and approved by Benjamin Parsons, BSc, MSc Geology, MAusIMM \(CP\#222568\) for Mineral Resources and Anton Chan, B.Eng \(Mining\), MS \(Earth Science\), P.Eng., MMSAQP \(\#01546QP\) for Mineral Reserves, both of SRK Consulting \(U.S.\), Inc., and reviewed by Paul Chawrun P.Eng., EVP & COO, for the Company, who are all qualified persons within the meaning of NI 43-101 and S-K 1300.

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: The technical report was prepared under National Instrument 43-101 – Standards of Disclosure for Mineral Projects \('NI 43-101'\).

Evidence · text

> a technical report prepared under National Instrument 43-101 – Standards of Disclosure for Mineral Projects \("NI 43-101"\)

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: The document explicitly states the cutoff grades used for both mineral reserves and resources.

Evidence · text

> Mineral Reserves are reported using a stopecenter of gravity \("CoG"\) range of 4.42 g/t \(0.13 oz/st\) Au – 6.41 g/t \(0.19 oz/st\) Au and an incremental processing CoGrange of 1.51 g/t \(0.04 oz/st\) Au – 2.91 g/t \(0.09 oz/st\) Au depending on the processing method.

**DFS-Supporting**

Polarity: neutral

Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence.

Why it applies: The document is a Feasibility Study, which is the highest level of technical study to support project development.

Evidence · text

> i-80 Gold Announces Positive Feasibility Study and Initial Mineral Reserves for Granite Creek Underground

**Resource Update**

Polarity: neutral

Definition: Revised estimate for an existing resource — compare to prior to assess progress.

Why it applies: The document presents an 'updated underground mineral resource estimate' compared to a previous PEA.

Evidence · text

> The updated underground mineral resource estimate included in the FS incorporates approximately 36,470 meters of drilling from 164 core holes conducted between 2023 through the end of 2025, relative to the resource estimate that formed the basis of the PEA published in March 2025.

**Maiden Resource**

Polarity: neutral

Definition: First formal MRE for the project — establishes baseline but typically exploration-stage with high Inferred component.

Why it applies: The document announces 'Initial Mineral Reserves' for the project.

Evidence · text

> Initial Proven and Probable Mineral Reserves of 2.20 million tonnes \("Mt"\) grading 7.87 grams per tonne \("g/t"\) gold \("Au"\) containing 556,500 ounces \("oz"\) of gold \("Au"\).

**Refractory Ore**

Polarity: negative

Definition: Ore requires oxidation/pressure treatment before recovery — a processing and recovery risk.

Why it applies: Metallurgical testing demonstrated that the ore contains 'predominantly single refractory material and require an oxidation process to increase gold extraction'.

Evidence · text

> Metallurgical testing has demonstrated that the Ogee, Otto and South Pacific zones at Granite Creek Underground contain predominantly single refractory material and require an oxidation process to increase gold extraction using cyanidation.

**No QA/QC Disclosure**

Polarity: negative

Story-specific tag

Definition: Release does not disclose QA/QC — lab certification, CP/QP sign-off and assay protocols cannot be checked from this document.

Why it applies: Historical drill results for the CX Zone are mentioned to lack QA/QC data.

Evidence · text

> No QA/QC data is available for these results, however these holes were found to be acceptable for use in the 2026 Granite Creek open pit resource estimate as conducted by Global Resource Engineering \(GRE\).

**Stale Data Re-release**

Polarity: negative

Story-specific tag

Definition: Historical results re-announced with no new assays or reinterpretation — low genuine novelty.

Why it applies: The document references 'Previous drilling in the CX Zone includes high-grade intercepts from legacy holes' from 1997 and 1995, which are historical results.

Evidence · text

> Previous drilling in the CX Zone includes high-grade intercepts from legacy holes, including 18.0 g/t Au over 9.1 m in hole HPR 078 and 15.3 g/t Au over 9.1 m in RHC-1763, and i-80 hole of 36.4 g/t Au over 9.1 m in iGM21-06.\(9\)

**Mill Route**

Polarity: neutral

Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\).

Why it applies: The processing strategy involves the company's wholly owned Lone Tree autoclave and carbon-in-leach \(CIL\) plant.

Evidence · text

> Lone Tree autoclave and carbon-in-leach plant

**POX/BIOX Route**

Polarity: neutral

Definition: Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX.

Why it applies: The processing strategy for refractory material involves 'acid pressure oxidation \("POX"\) conditions'.

Evidence · text

> acid pressure oxidation \("POX"\) conditions

**Gravity Route**

Polarity: neutral

Definition: Gravity separation forms a material part of the flowsheet.

Why it applies: the document describes a gravity route \("gravity"\)

## Extracted facts

Stored fact records: 26. Some facts used in scoring do not have a stored record.

## Resource Estimates (25)

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-0)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:ded839cd2c23871ebe9c
- Deposit or zone: Ogee
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 71000
- Grade: 9.34
- Grade Unit: g/t
- Contained Metal: 21.2
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: High-grade Proven reserve for the Ogee zone, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: High grade for an underground gold reserve.

- Positive factor: Proven category indicates high confidence in the estimate.

- Positive factor: Part of initial mineral reserves for the project.

Evidence · table

> 9.34

Context: 71

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-1)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:086c2ec83da971e0eda1
- Deposit or zone: Otto
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 171000
- Grade: 7.04
- Grade Unit: g/t
- Contained Metal: 38.7
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Proven reserve for the Otto zone, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Strong grade for an underground gold reserve.

- Positive factor: Proven category indicates high confidence in the estimate.

- Positive factor: Part of initial mineral reserves for the project.

Evidence · table

> 7.04

Context: 171

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-2)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:ab2b059c9a84c0c9e55a
- Deposit or zone: South Pacific
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 40000
- Grade: 11.21
- Grade Unit: g/t
- Contained Metal: 14.5
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Exceptional-grade Proven reserve for the South Pacific zone, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Exceptional grade for an underground gold reserve.

- Positive factor: Proven category indicates high confidence in the estimate.

- Positive factor: Part of initial mineral reserves for the project.

Evidence · table

> 11.21

Context: 40

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-3)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:78429c4a9a11ed89e98d
- Deposit or zone: Stockpile
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 26000
- Grade: 7.33
- Grade Unit: g/t
- Contained Metal: 6.2
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Proven reserve from stockpile, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Strong grade for a gold reserve.

- Positive factor: Proven category indicates high confidence in the estimate.

- Positive factor: Represents already mined material, reducing future mining risk.

Evidence · table

> 7.33

Context: 26

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### probable

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-4)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:e90567a8a1c40ff64270
- Deposit or zone: Ogee
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: probable
- Tonnes: 88000
- Grade: 7.95
- Grade Unit: g/t
- Contained Metal: 22.4
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Probable reserve for the Ogee zone, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Strong grade for an underground gold reserve.

- Positive factor: Probable category indicates good confidence in the estimate.

- Positive factor: Part of initial mineral reserves for the project.

Evidence · table

> 7.95

Context: 88

#### Tags used in scoring

**Probable Reserve**

Polarity: positive

Definition: Indicated Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "probable"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### probable

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-5)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:a5da6a7100671010bcaf
- Deposit or zone: Otto
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: probable
- Tonnes: 366000
- Grade: 6.7
- Grade Unit: g/t
- Contained Metal: 78.8
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Probable reserve for the Otto zone, contributing to the initial mineral reserves for the project, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Strong grade for an underground gold reserve.

- Positive factor: Probable category indicates good confidence in the estimate.

- Positive factor: Part of initial mineral reserves for the project.

Evidence · table

> 6.70

Context: 366

#### Tags used in scoring

**Probable Reserve**

Polarity: positive

Definition: Indicated Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "probable"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### probable

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-6)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:bbd4ce7157d188ea5fd0
- Deposit or zone: South Pacific
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: probable
- Tonnes: 1437000
- Grade: 8.11
- Grade Unit: g/t
- Contained Metal: 374.7
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: High-grade Probable reserve for the South Pacific zone, representing the largest portion of initial mineral reserves, with a cutoff grade of 4.42 g/t Au.

- Positive factor: High grade for an underground gold reserve.

- Positive factor: Probable category indicates good confidence in the estimate.

- Positive factor: Largest component of initial mineral reserves for the project.

Evidence · table

> 8.11

Context: 1,437

#### Tags used in scoring

**Probable Reserve**

Polarity: positive

Definition: Indicated Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "probable"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-7)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:44f94abfc9c1338e30f4
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 308000
- Grade: 8.13
- Grade Unit: g/t
- Contained Metal: 80.6
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Proven reserves for the Granite Creek Underground project, with a high average grade of 8.13 g/t Au and a cutoff grade of 4.42 g/t Au.

- Positive factor: High grade for an underground gold reserve.

- Positive factor: Proven category indicates high confidence in the estimate.

- Positive factor: Represents the total Proven reserves for the project.

Evidence · table

> 8.13

Context: 308

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### probable

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-8)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:9487a1f013e1849da06f
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: probable
- Tonnes: 1890000
- Grade: 7.83
- Grade Unit: g/t
- Contained Metal: 475.9
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Probable reserves for the Granite Creek Underground project, with a high average grade of 7.83 g/t Au and a cutoff grade of 4.42 g/t Au.

- Positive factor: High grade for an underground gold reserve.

- Positive factor: Probable category indicates good confidence in the estimate.

- Positive factor: Represents the total Probable reserves for the project.

Evidence · table

> 7.83

Context: 1,890

#### Tags used in scoring

**Probable Reserve**

Polarity: positive

Definition: Indicated Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "probable"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### proven

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-9)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: reserve
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Anton Chan, Benjamin Parsons
- Resource group id: resource:9ccb7d3c3aa70b62c67d
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: proven
- Tonnes: 2198000
- Grade: 7.87
- Grade Unit: g/t
- Contained Metal: 556.5
- Contained Unit: koz
- Cutoff Grade: 4.42
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Proven and Probable Mineral Reserves for the Granite Creek Underground project, representing a significant and high-grade initial reserve base, with a cutoff grade of 4.42 g/t Au.

- Positive factor: Initial Proven and Probable Mineral Reserves established, providing a robust foundation for future production.

- Positive factor: High grade for an underground gold reserve.

- Positive factor: Significant contained metal for the project.

Evidence · table

> 7.87

Context: 2,198

#### Tags used in scoring

**Proven Reserve**

Polarity: positive

Definition: Measured Resource with demonstrated economic viability after applying modifying factors.

Why it applies: category is "proven"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### measured

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-10)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:cdd259eb3cfdaf5e94e2
- Deposit or zone: Ogee
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: measured
- Tonnes: 231000
- Grade: 7.88
- Grade Unit: g/t
- Contained Metal: 58.5
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: High-grade Measured resource for the Ogee zone, contributing to the substantial increase in Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: High grade for an underground gold resource.

- Positive factor: Measured category indicates high confidence in the estimate.

- Positive factor: Contributes to the significant increase in M&I resources.

Evidence · table

> 7.88

Context: 231

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### measured

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-11)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:a6ed1451ceaf805e50f2
- Deposit or zone: Otto
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: measured
- Tonnes: 310000
- Grade: 6.69
- Grade Unit: g/t
- Contained Metal: 66.6
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Measured resource for the Otto zone, contributing to the substantial increase in Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Positive factor: Measured category indicates high confidence in the estimate.

- Positive factor: Contributes to the significant increase in M&I resources.

Evidence · table

> 6.69

Context: 310

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### measured

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-12)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:7bc5afebbe197a00f6e8
- Deposit or zone: South Pacific
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: measured
- Tonnes: 65000
- Grade: 9.85
- Grade Unit: g/t
- Contained Metal: 20.7
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Exceptional-grade Measured resource for the South Pacific zone, contributing to the substantial increase in Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Exceptional grade for an underground gold resource.

- Positive factor: Measured category indicates high confidence in the estimate.

- Positive factor: Contributes to the significant increase in M&I resources.

Evidence · table

> 9.85

Context: 65

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-13)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:920bb341e6b64c4c8ef3
- Deposit or zone: Ogee
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Tonnes: 321000
- Grade: 7.06
- Grade Unit: g/t
- Contained Metal: 72.9
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Indicated resource for the Ogee zone, contributing to the substantial increase in Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Positive factor: Indicated category indicates good confidence in the estimate.

- Positive factor: Contributes to the significant increase in M&I resources.

Evidence · table

> 7.06

Context: 322

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-14)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:7f708c15d9c6af0fc741
- Deposit or zone: Otto
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Tonnes: 746000
- Grade: 6.26
- Grade Unit: g/t
- Contained Metal: 150.2
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Indicated resource for the Otto zone, contributing to the substantial increase in Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Positive factor: Indicated category indicates good confidence in the estimate.

- Positive factor: Contributes to the significant increase in M&I resources.

Evidence · table

> 6.26

Context: 746

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-15)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:ca1ffce1b404ca51dd31
- Deposit or zone: South Pacific
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Tonnes: 2055000
- Grade: 7.42
- Grade Unit: g/t
- Contained Metal: 490.4
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: High-grade Indicated resource for the South Pacific zone, representing the largest portion of the increased Measured and Indicated resources, with a cutoff grade of 3.75 g/t Au.

- Positive factor: High grade for an underground gold resource.

- Positive factor: Indicated category indicates good confidence in the estimate.

- Positive factor: Largest component of the significant increase in M&I resources.

Evidence · table

> 7.42

Context: 2,055

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### measured

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-16)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:a3ff3d5f3f6523e8bd0d
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: measured
- Tonnes: 606000
- Grade: 7.49
- Grade Unit: g/t
- Contained Metal: 145.8
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Measured resources for the Granite Creek Underground project, with a high average grade of 7.49 g/t Au and a cutoff grade of 3.75 g/t Au.

- Positive factor: High grade for an underground gold resource.

- Positive factor: Measured category indicates high confidence in the estimate.

- Positive factor: Represents the total Measured resources for the project.

Evidence · table

> 7.49

Context: 606

#### Tags used in scoring

**Measured Resource**

Polarity: positive

Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves.

Why it applies: category is "measured"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-17)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:a2ee534985d2ec884cd5
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Tonnes: 3122000
- Grade: 7.11
- Grade Unit: g/t
- Contained Metal: 713.5
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Indicated resources for the Granite Creek Underground project, with a high average grade of 7.11 g/t Au and a cutoff grade of 3.75 g/t Au.

- Positive factor: High grade for an underground gold resource.

- Positive factor: Indicated category indicates good confidence in the estimate.

- Positive factor: Represents the total Indicated resources for the project.

Evidence · table

> 7.11

Context: 3,122

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-18)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:0cd3b8e94fccb2c23af6
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Tonnes: 3728000
- Grade: 7.17
- Grade Unit: g/t
- Contained Metal: 859.3
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Measured and Indicated resources for the Granite Creek Underground project, showing a substantial increase and high average grade, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Significant increase \(229%\) in Measured and Indicated Mineral Resources, indicating improved geological confidence and potential for further conversion.

- Positive factor: High grade for an underground gold resource.

- Positive factor: Represents the total Measured and Indicated resources for the project.

Evidence · table

> 7.17

Context: 3,729

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### inferred

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-19)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:ae2c6cfa5939bd50327d
- Deposit or zone: Ogee
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: inferred
- Tonnes: 38000
- Grade: 6.7
- Grade Unit: g/t
- Contained Metal: 8.3
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Inferred resource for the Ogee zone, representing a smaller component of the overall resource, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Negative factor: Inferred category indicates lower geological confidence.

Evidence · table

> 6.70

Context: 39

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### inferred

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-20)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:85498eecac69d1b0eb8d
- Deposit or zone: Otto
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: inferred
- Tonnes: 425000
- Grade: 7.63
- Grade Unit: g/t
- Contained Metal: 104.4
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: High-grade Inferred resource for the Otto zone, contributing to the overall resource base, with a cutoff grade of 3.75 g/t Au.

- Positive factor: High grade for an underground gold resource.

- Negative factor: Inferred category indicates lower geological confidence.

Evidence · table

> 7.63

Context: 425

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### inferred

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-21)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:2db84ccc787e5a7f3a9b
- Deposit or zone: South Pacific
- Ownership percent: 91.67 %
- Resource basis: attributable

#### Resource Data

- Category: inferred
- Tonnes: 418000
- Grade: 6.53
- Grade Unit: g/t
- Contained Metal: 87.4
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Strong-grade Inferred resource for the South Pacific zone, with a lower attributable ownership of 91.67% and a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Negative factor: Inferred category indicates lower geological confidence.

- Negative factor: Lower attributable ownership percentage for this portion of the resource.

Evidence · table

> 6.53

Context: 429

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### inferred

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-22)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:1619f41f9806733fbeb3
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: inferred
- Tonnes: 882000
- Grade: 7.06
- Grade Unit: g/t
- Contained Metal: 200.1
- Contained Unit: koz
- Cutoff Grade: 3.75
- Cutoff Unit: g/t

#### Prior Estimate

- Resource Date: 2026-03-31

#### Metal Equivalent

- Assumptions Disclosed: Yes

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Total Inferred resources for the Granite Creek Underground project, with a strong average grade of 7.06 g/t Au, but representing a lower confidence category and a decrease from prior estimates due to conversion, with a cutoff grade of 3.75 g/t Au.

- Positive factor: Strong grade for an underground gold resource.

- Negative factor: Inferred category indicates lower geological confidence.

- Negative factor: Overall Inferred resources decreased by 38% as material was converted to higher categories.

Evidence · table

> 7.06

Context: 893

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Disclosed**

Polarity: positive

Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison.

Why it applies: cutoff\_grade is stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### indicated

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-23)

Granite Creek open pit · gold

#### Identity

- Project: Granite Creek open pit
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:533cc28490cd02b033cc
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: indicated
- Grade: 0.97
- Grade Unit: g/t
- Contained Metal: 1591000
- Contained Unit: oz

#### Prior Estimate

- Resource Date: 2026-03-31

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Updated Measured and Indicated open pit resource for Granite Creek, showing a significant contained gold amount and an 11% increase from prior estimates.

- Positive factor: Significant contained gold ounces for an open pit resource.

- Positive factor: Measured and Indicated categories indicate good confidence.

- Positive factor: Open pit M&I resources increased by 11%.

- Negative factor: Lower grade typical for open pit, but still below strong threshold for porphyry.

Evidence · text

> 1,591,000 oz Au grading 0.97 g/t Au in the Measured and Indicated categories

#### Tags used in scoring

**Indicated Resource**

Polarity: positive

Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves.

Why it applies: category is "indicated"

**Cut-off Undisclosed**

Polarity: negative

Definition: High-grade interval reported without stating the cut-off grade used for compositing.

Why it applies: no cutoff\_grade was stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

### inferred

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-resource-facts-24)

Granite Creek open pit · gold

#### Identity

- Project: Granite Creek open pit
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Resource scope

- Estimate type: resource
- Reporting standards: ni\_43\_101, sec\_sk1300
- QP Signed: Yes
- Qualified person names: Benjamin Parsons, Anton Chan
- Resource group id: resource:b4774a31762f83480591
- Ownership percent: 100 %
- Resource basis: attributable

#### Resource Data

- Category: inferred
- Grade: 0.81
- Grade Unit: g/t
- Contained Metal: 99800
- Contained Unit: oz

#### Prior Estimate

- Resource Date: 2026-03-31

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: Updated Inferred open pit resource for Granite Creek, showing an increase from prior estimates but remaining in a lower confidence category.

- Positive factor: Contributes to the overall resource base.

- Positive factor: Open pit Inferred resources increased by 33%.

- Negative factor: Inferred category indicates lower geological confidence.

- Negative factor: Lower grade typical for open pit, but still below strong threshold for porphyry.

Evidence · text

> 99,800 oz Au grading at 0.81 g/t Au in the Inferred category

#### Tags used in scoring

**Inferred Resource**

Polarity: negative

Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone.

Why it applies: category is "inferred"

**Cut-off Undisclosed**

Polarity: negative

Definition: High-grade interval reported without stating the cut-off grade used for compositing.

Why it applies: no cutoff\_grade was stated

**QP/CP Signed**

Polarity: positive

Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience.

Why it applies: qp\_signed is true

**NI 43-101 Compliant**

Polarity: positive

Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard.

Why it applies: reporting\_standards includes ni\_43\_101

## Metallurgical Results (1)

### POX, CIL

[Link to this fact](https://atlas-staging.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--115a7ff5-3c76-4b92-9275-f44031cb2e8a#fact-metallurgical-facts-25)

Granite Creek Underground · gold

#### Identity

- Project: Granite Creek Underground
- Commodity: gold
- Region: usa\_nv
- Reported Region: Nevada, USA
- Ticker: IAU

#### Test Work

- Program Status: detailed
- Test Type: POX, CIL
- Processing Route: acid pressure oxidation \(POX\) for refractory, carbon-in-leach \(CIL\) for oxide

#### Recovery

- Recovery: 87 %
- Recovery Basis: actual\_test
- Head Grade: 7.87
- Head Grade Unit: g/t

#### Review

- Needs Review: No
- Historical: No

#### Dates

- Event date: 2026-09-21T00:00:00.000Z

Reasoning: The metallurgical testwork supports an average gold recovery of 87% for the Granite Creek Underground ore, utilizing an optimized processing strategy involving POX for refractory and CIL for oxide material, despite the inherent complexity of the ore.

- Positive factor: High average gold recovery \(87%\) for the overall processing strategy.

- Positive factor: Metallurgical testing demonstrated effective oxidation for refractory material.

- Positive factor: Optimized processing strategy using company's own plant is expected to reduce costs.

- Negative factor: Ore is predominantly refractory, requiring complex and potentially costly oxidation process.

Evidence · table

> 87 %

Context: Average Gold Recovery

#### Tags used in scoring

**Mill Route**

Polarity: neutral

Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\).

Why it applies: processing\_route matches the mill\_cil signal

**POX/BIOX Route**

Polarity: neutral

Definition: Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX.

Why it applies: processing\_route matches the pox\_biox signal

## How Atlas produces this analysis

Minestarters Atlas uses automated extraction to summarize mining announcements, identify reported measurements, and classify supporting evidence. Sentiment reflects the extracted narrative and classification rules; it is an interpretation, not a reported measurement. Evidence quotes and context are provided where available. Missing data, low-confidence results, and review flags indicate limitations. Check the original publisher announcement before relying on an interpretation.