# McEwen Files NI 43-101 Technical Reports: Grey Fox Prefeasibility Study in Ontario and Lookout Mountain and Windfall Mineral Resource Estimate in Nevada Canonical Atlas analysis: https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb Original source: https://www.globenewswire.com/news-release/2026/07/22/3331605/37420/en/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontario-and-lookout-mountain-and-windfall-mineral-resource-estimate-in-nevada.html Publisher: globenewswire Original announcement: 2026-07-22T00:00:00.000Z Analysis by Minestarters Atlas Atlas analysis published: Unknown date Atlas analysis updated: Unknown date - Company: McEwen Inc. - Ticker: MUX - Exchange: Unavailable - Region: Nevada - Primary commodity: Gold - Secondary commodities: Silver, Copper - Document categories: Resource update, Other - Extracted: 2026-08-20 20:01:06 UTC Narrative sentiment: 0.60 · Bullish ## Minestarters Atlas summary McEwen Inc. has filed NI 43-101 technical reports including a Prefeasibility Study for the Grey Fox project in Ontario, which reports 9.41 Mt of Probable Reserves at 3.24 g/t Au. Additionally, the company filed resource estimates for the Lookout Mountain and Windfall deposits in Nevada, totaling over 890,000 gold ounces in Indicated and Inferred resources. Reasoning: The filing includes a Prefeasibility Study for Grey Fox \(reporting reserves\) and updated Mineral Resource Estimates for Nevada assets. - Positive factor: Probable Reserves reported for Grey Fox - Positive factor: Significant gold ounces in Lookout Mountain and Windfall resources - Positive factor: High proportion of oxide mineralization amenable to heap leach - Negative factor: Resource estimates for Lookout Mountain and Windfall are restatements of previous announcements Facts used in scoring: 7 ## Classification and evidence **Probable Reserve** Polarity: positive Definition: Indicated Resource with demonstrated economic viability after applying modifying factors. Why it applies: Grey Fox project reports 9.41 Mt of Probable Reserves. Evidence · text > supported by Probable Mineral Reserves of 9.41 million tonnes **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: Lookout Mountain and Windfall contain significant Inferred resources. Evidence · text > 262,000 gold ounces in Inferred Mineral Resources **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: Multiple Qualified Persons are named for both technical reports. Evidence · text > The Grey Fox Report was prepared by the following Qualified Persons ## Extracted facts Stored fact records: 7. Some facts used in scoring do not have a stored record. ## Resource Estimates (7) ### probable [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-0) Grey Fox · gold #### Identity - Project: Grey Fox - Commodity: gold - Region: canada\_on - Reported Region: Ontario - Ticker: MUX #### Resource Data - Category: probable - Tonnes: 9410000 - Grade: 3.24 - Grade Unit: g/t - Contained Metal: 980300 - Contained Unit: oz #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Probable reserves reported as part of a PFS. - Positive factor: Strong grade and tonnage for reserves Evidence · text > Probable Mineral Reserves of 9.41 million tonnes grading 3.24 g/t Au and containing 980,300 gold ounces ### indicated [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-1) Grey Fox · gold #### Identity - Project: Grey Fox - Commodity: gold - Region: canada\_on - Reported Region: Ontario - Ticker: MUX #### Resource Data - Category: indicated - Tonnes: 9680000 - Grade: 2.25 - Grade Unit: g/t - Contained Metal: 701000 - Contained Unit: oz #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Indicated resource component of the Grey Fox project. - Positive factor: Significant indicated resource Evidence · text > 9.68 million tonnes at 2.25 g/t Au for 701,000 gold ounces Indicated ### inferred [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-2) Grey Fox · gold #### Identity - Project: Grey Fox - Commodity: gold - Region: canada\_on - Reported Region: Ontario - Ticker: MUX #### Resource Data - Category: inferred - Tonnes: 4700000 - Grade: 2.57 - Grade Unit: g/t - Contained Metal: 388000 - Contained Unit: oz #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Inferred resource component of the Grey Fox project. - Positive factor: High grade for inferred category Evidence · text > 4.70 million tonnes at 2.57 g/t Au for 388,000 gold ounces Inferred ### indicated [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-3) Lookout Mountain · gold Historical result Needs review: historical\_restatement #### Identity - Project: Lookout Mountain - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: MUX #### Resource Data - Category: indicated - Tonnes: 19570000 - Grade: 0.64 - Grade Unit: g/t - Contained Metal: 402300 - Contained Unit: oz #### Review - Needs Review: Yes - Review Reason: historical\_restatement - Historical: Yes - Historical Source Date: 2026-03-12T00:00:00.000Z #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Indicated resource for Lookout Mountain, previously announced in March 2026. - Positive factor: Large tonnage indicated resource - Negative factor: Restatement of previous estimate Evidence · text > Lookout Mountain: Indicated Mineral Resources of 19.57 million tonnes at 0.64 g/t Au, containing 402,300 gold ounces ### inferred [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-4) Lookout Mountain · gold Historical result Needs review: historical\_restatement #### Identity - Project: Lookout Mountain - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: MUX #### Resource Data - Category: inferred - Tonnes: 7290000 - Grade: 0.57 - Grade Unit: g/t - Contained Metal: 134200 - Contained Unit: oz #### Review - Needs Review: Yes - Review Reason: historical\_restatement - Historical: Yes - Historical Source Date: 2026-03-12T00:00:00.000Z #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Inferred resource for Lookout Mountain, previously announced in March 2026. - Negative factor: Restatement of previous estimate Evidence · text > Inferred Mineral Resources of 7.29 million tonnes at 0.57 g/t Au, containing 134,200 gold ounces ### indicated [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-5) Windfall · gold Historical result Needs review: historical\_restatement #### Identity - Project: Windfall - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: MUX #### Resource Data - Category: indicated - Tonnes: 9400000 - Grade: 0.75 - Grade Unit: g/t - Contained Metal: 227500 - Contained Unit: oz #### Review - Needs Review: Yes - Review Reason: historical\_restatement - Historical: Yes - Historical Source Date: 2026-05-06T00:00:00.000Z #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Indicated resource for Windfall, previously announced in May 2026. - Negative factor: Restatement of previous estimate Evidence · text > Windfall: Indicated Mineral Resources of 9.40 million tonnes at 0.75 g/t Au, containing 227,500 gold ounces ### inferred [Link to this fact](https://atlas-staging.minestarters.com/news/mcewen-files-ni-43-101-technical-reports-grey-fox-prefeasibility-study-in-ontari--21f6c13e-3cfb-4eca-b92c-6afc4321b8fb#fact-resource-facts-6) Windfall · gold Historical result Needs review: historical\_restatement #### Identity - Project: Windfall - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: MUX #### Resource Data - Category: inferred - Tonnes: 2600000 - Grade: 1.53 - Grade Unit: g/t - Contained Metal: 127800 - Contained Unit: oz #### Review - Needs Review: Yes - Review Reason: historical\_restatement - Historical: Yes - Historical Source Date: 2026-05-06T00:00:00.000Z #### Dates - Event date: 2026-07-22T00:00:00.000Z Reasoning: Inferred resource for Windfall, previously announced in May 2026. - Positive factor: Stronger grade for inferred category - Negative factor: Restatement of previous estimate Evidence · text > Inferred Mineral Resources of 2.60 million tonnes at 1.53 g/t Au, containing 127,800 gold ounces ## 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.