# Grande Portage Resources Reports Positive Results from Preliminary Strength Testing of Mine Backfill Materials Canonical Atlas analysis: https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d Original source: https://money.tmx.com/en/quote/GPG/news/6446637191569929/grande-portage-resources-reports-positive-results-from-preliminary-strength-test Publisher: tmx Original announcement: 2026-07-06T08:00:00.000Z Analysis by Minestarters Atlas Atlas analysis published: Unknown date Atlas analysis updated: Unknown date - Company: Grande Portage Resources Ltd. - Ticker: GPG - Exchange: TSX - Region: Alaska - Primary commodity: Gold - Secondary commodities: Silver - Document categories: Metallurgy, Resource update - Extracted: 2026-08-23 14:38:14 UTC Narrative sentiment: 0.60 · Bullish ## Minestarters Atlas summary Grande Portage Resources has reported positive preliminary strength testing results for its cemented rockfill \(CRF\) backfill materials at the New Amalga Gold project. The results met or exceeded strength criteria for the planned overhand longhole stoping method, supporting a small-footprint underground mining strategy. Reasoning: The announcement reports successful preliminary strength testing of cemented rockfill \(CRF\), which validates the company's waste management strategy and de-risks the planned underground mining method. - Positive factor: Successful preliminary backfill strength testing - Positive factor: Supports small-footprint underground mining strategy - Positive factor: De-risking milestone for mine development Facts used in scoring: 5 ## Classification and evidence **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: Kyle Mehalek, P.E., is named as the QP who has reviewed and approved the technical disclosure. Evidence · text > Kyle Mehalek, P.E.., is the QP within the meaning of NI 43-101 and has reviewed and approved the technical disclosure in this release. **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: The resource estimate and technical disclosures are prepared in compliance with NI 43-101. Evidence · text > The Company's updated NI43-101 Mineral Resource Estimate \(MRE\)... ## Extracted facts Stored fact records: 5. Some facts used in scoring do not have a stored record. ## Metallurgical Results (5) ### Fact 1 [Link to this fact](https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d#fact-metallurgical-facts-0) gold #### Identity - Commodity: gold - Ticker: GPG #### Test Work - Sample: Indicated Resource #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-06T00:00:00.000Z Reasoning: Standard Indicated resource component of the project. Evidence · text > Indicated Resource of 1,438,500 ounces of gold at an average grade of 9.47 g/t Au \(4,726,000 tonnes\) ### Fact 2 [Link to this fact](https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d#fact-metallurgical-facts-1) gold #### Identity - Commodity: gold - Ticker: GPG #### Test Work - Sample: Inferred Resource #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-06T00:00:00.000Z Reasoning: Standard Inferred resource component of the project. Evidence · text > Inferred Resource of 515,700 ounces of gold at an average grade of 8.85 g/t Au \(1,813,000 tonnes\) ### Fact 3 [Link to this fact](https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d#fact-metallurgical-facts-2) silver #### Identity - Commodity: silver - Ticker: GPG #### Test Work - Sample: Indicated Resource #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-06T00:00:00.000Z Reasoning: Byproduct silver resource component. Evidence · text > Indicated Resource of 891,600 ounces of silver at an average grade of 5.86 g/t Ag \(4,726,000 tonnes\) ### Fact 4 [Link to this fact](https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d#fact-metallurgical-facts-3) silver #### Identity - Commodity: silver - Ticker: GPG #### Test Work - Sample: Inferred Resource #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-06T00:00:00.000Z Reasoning: Byproduct silver resource component. Evidence · text > Inferred Resource of 390,600 ounces of silver at an average grade of 7.33 g/t silver \(1,813,000 tonnes\) ### strength testing [Link to this fact](https://atlas-staging.minestarters.com/news/grande-portage-resources-reports-positive-results-from-preliminary-strength-test--a4f06d6b-ee31-4861-8f0f-62cad29df71d#fact-metallurgical-facts-4) gold #### Identity - Commodity: gold - Ticker: GPG #### Test Work - Program Status: preliminary - Test Type: strength testing - Sample: CRF samples \(4% cement binder\) #### Reagents - Reagent Notes: 4% cement binder content; tested for uniaxial compressive strength \(UCS\) after 10-day and 17-day cure times #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-06T00:00:00.000Z Reasoning: Successful preliminary strength testing of backfill material validates the mining strategy. - Positive factor: Met or exceeded strength criteria for primary mining method Evidence · text > All samples met or exceeded the preliminary strength criteria selected for overhand longhole stoping ## 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.