# Corvus Gold Files NI 43-101 Technical Report and Preliminary Economic Assessment for its North Bullfrog Project, Nevada Canonical Atlas analysis: https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f Original source: https://money.tmx.com/en/quote/KOR/news/66384696/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment Publisher: tmx Original announcement: 2015-08-04T12:00:00.000Z Analysis by Minestarters Atlas Atlas analysis published: Unknown date Atlas analysis updated: Unknown date - Company: Corvus Gold Inc. - Ticker: KOR - Exchange: TSX - Region: Nevada - Primary commodity: Gold - Secondary commodities: Silver - Document categories: Resource update, Metallurgy - Extracted: 2026-09-16 07:41:46 UTC Narrative sentiment: 0.80 · Bullish ## Minestarters Atlas summary Corvus Gold has filed an NI 43-101 compliant Preliminary Economic Assessment \(PEA\) for its North Bullfrog Project in Nevada, highlighting strong economics with a post-tax NPV\(5%\) of US$246M and an IRR of 38% at a US$1,200 gold price. The report details an updated mineral resource estimate, showing a significant increase in Measured & Indicated confidence for the YellowJacket deposit, with average gold recoveries of 86.8% for mill processing and 73.9% for heap leaching. The PEA projects a low life-of-mine cash cost of US$635/oz gold. Reasoning: The PEA and updated resource estimate demonstrate strong economic potential for the North Bullfrog Project with robust financial metrics, improved resource confidence, and favorable metallurgical recoveries for gold, despite the preliminary nature of the study and low silver heap leach recovery. - Positive factor: Strong project economics demonstrated by PEA with high IRR and NPV at $1,200 gold price. - Positive factor: Low projected life-of-mine cash costs of US$635/oz Au. - Positive factor: Significant increase in Measured & Indicated resource confidence for the YellowJacket deposit \(91% M&I up from <20%\). - Positive factor: High gold recoveries for both mill \(86.8%\) and heap leach \(73.9%\) processing routes. - Positive factor: New resource calculation based on a lower gold price \($1,200 vs $1,300 previously\), indicating robustness. - Negative factor: PEA is preliminary in nature and based on assumptions that require further evaluation. - Negative factor: A significant portion of the resource remains in the Inferred category, which is speculative. - Negative factor: Very low silver recovery for heap leach processing \(6%\). Facts used in scoring: 18 ## Classification and evidence **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: The document is an 'NI 43-101 Technical Report' and states that 'all resource estimates contained in or incorporated by reference in this press release have been prepared in accordance with NI 43-101'. Evidence · text > NI 43-101 Technical Report **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: Jeffrey A. Pontius, Carl E. Brechtel, and Scott E. Wilson are named as Qualified Persons who supervised and approved the disclosure. Evidence · text > Jeffrey A. Pontius \(CPG 11044\), a qualified person as defined by NI 43-101, has supervised the preparation of the scientific and technical information that form the basis for this news release and has reviewed and approved the disclosure herein. ... Carl E. Brechtel , \(Nevada PE 008744 and Registered Member 353000 of SME\), a qualified person as defined by NI 43-101, has coordinated execution of the work outlined in this news release and has reviewed and approved the disclosure herein. ... Mr. Scott E. Wilson , CPG, President of Metal Mining Consultants Inc., is an independent consulting geologist specializing in Mineral Reserve and Resource calculation reporting, mining project analysis and due diligence evaluations. He is acting as the Qualified Person, as defined in NI 43-101, for the overall technical report, and the Mineral Resource estimate. **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 resource estimate includes a 'Measured' category for both gold and silver in milling and heap leach material. Evidence · table > Measured Context: Measured **Indicated Resource** Polarity: positive Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves. Why it applies: The resource estimate includes an 'Indicated' category for both gold and silver in milling and heap leach material. Evidence · table > Indicated Context: Indicated **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: The resource estimate includes an 'Inferred' category for both gold and silver in milling and heap leach material, which is considered speculative. Evidence · table > Inferred Context: Inferred **Category Upgrade** Polarity: positive Definition: Resource confidence improved — Inferred upgraded to Indicated, or Indicated to Measured. De-risking signal. Why it applies: YellowJacket/mill resource confidence increased significantly with 91% in Measured & Indicated category up from <20% in 2014 resource. Evidence · text > YellowJacket/mill resource confidence increased significantly with 91% in Measured & Indicated category up from <20% in 2014 resource **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: The document announces a 'new resource calculation' and a 'Preliminary Economic Assessment' based on this updated resource. Evidence · text > new resource calculation **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 mill and heap leach material in the resource estimate. Evidence · text > 0.52 g/t gold mill breakeven grade and 0.15 g/t gold heap leach breakeven grade **High Recovery** Polarity: positive Definition: Recovery at or above the exceptional band for the commodity and processing route. Why it applies: The average gold recovery for mill processing is 86.8%, which is strong for a CIL mill route. Evidence · table > 86.8% Context: Average Gold Recovery - Mill **Heap Leach Route** Polarity: neutral Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected. Why it applies: The PEA assumes 'heap leach processing of low grade mineralized material'. Evidence · text > heap leach processing of low grade mineralized material **Mill Route** Polarity: neutral Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\). Why it applies: The PEA assumes 'milling of higher grade mineralization with gravity-cyanide leaching'. Evidence · text > milling of higher grade mineralization with gravity-cyanide leaching **Bench Scale Only** Polarity: negative Definition: Only preliminary bench tests completed — no locked-cycle or pilot work. Why it applies: Metallurgical recovery estimates are based on 'column leach testing data' and 'composite samples', which are bench-scale tests. Evidence · text > Heap leach metallurgical recovery estimates are based on column leach testing data for composite samples **Multi-Domain Tested** Polarity: positive Definition: Variability across ore domains \(oxide, transition, fresh\) has been addressed. Why it applies: Mill recoveries were estimated from 'two sets of metallurgical composite samples' and heap leach recoveries from '23 column leach tests' from '3 current resource areas', indicating variability testing. Evidence · text > A total of six different sample composites were created from PQ core developed in 2013 and 2014 drilling programs, and were tested to characterize the variation of vein and vein stockwork materials. Heap leach process recoveries were estimated based on the results of column leach testing of composite samples created from the 2012 PQ core metallurgical drilling program. A total of 23 sample composites from the 3 current resource areas were prepared from 2012 PQ core **Low Recovery** Polarity: negative Definition: Recovery below the weak band for the commodity and processing route. Why it applies: The average silver recovery for heap leach is 6%, which is very low. Evidence · table > 6% Context: Average Silver Recovery – Heap Leach **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: The document is a 'Preliminary Economic Assessment' which is an early-stage study. Evidence · text > Preliminary Economic Assessment **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: 18. Some facts used in scoring do not have a stored record. ## Resource Estimates (14) ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-0) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:71669687acd0ed842405 - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: measured - Tonnes: 3860000 - Grade: 2.55 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Measured resource for YellowJacket milling material shows a high gold grade, indicating strong economic potential and high geological confidence. - Positive factor: High gold grade for an open pit resource. - Positive factor: Highest confidence resource category \(Measured\). Evidence · table > 3.86 Context: Measured #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-1) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:71669687acd0ed842405 - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: measured - Tonnes: 3860000 - Grade: 19.7 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Measured resource for YellowJacket milling material includes a good silver grade, adding to the project's overall value with high geological confidence. - Positive factor: Good silver grade for an open pit resource. - Positive factor: Highest confidence resource category \(Measured\). Evidence · table > 19.70 Context: Measured #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-2) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:b266f7b35ce55118514e - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: measured - Tonnes: 300000 - Grade: 0.25 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Measured resource for disseminated heap leach material, while lower grade, is suitable for bulk tonnage heap leach operations and has high geological confidence. - Positive factor: Highest confidence resource category \(Measured\). - Positive factor: Low cutoff grade suitable for heap leach processing. Evidence · table > 0.30 Context: Measured #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-3) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:b266f7b35ce55118514e - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: measured - Tonnes: 300000 - Grade: 2.76 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Measured resource for disseminated heap leach material includes a silver grade, contributing to the overall project value with high geological confidence. - Positive factor: Highest confidence resource category \(Measured\). - Positive factor: Low cutoff grade suitable for heap leach processing. Evidence · table > 2.76 Context: Measured #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-4) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:a47a4f5b43eac5dfbd5e - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 1810000 - Grade: 1.53 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Indicated resource for YellowJacket milling material shows a good gold grade, providing confidence in the project's economic potential. - Positive factor: Good gold grade for an open pit resource. - Positive factor: High confidence resource category \(Indicated\). Evidence · table > 1.81 Context: Indicated #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-5) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:a47a4f5b43eac5dfbd5e - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 1810000 - Grade: 10.2 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Indicated resource for YellowJacket milling material includes a good silver grade, contributing to the project's overall value with high geological confidence. - Positive factor: Good silver grade for an open pit resource. - Positive factor: High confidence resource category \(Indicated\). Evidence · table > 10.20 Context: Indicated #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-6) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:3bfa7d75f46e61e2bd95 - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 22860000 - Grade: 0.3 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Indicated resource for disseminated heap leach material, while lower grade, is suitable for bulk tonnage heap leach operations and provides confidence in the project's economic potential. - Positive factor: High confidence resource category \(Indicated\). - Positive factor: Low cutoff grade suitable for heap leach processing. Evidence · table > 22.86 Context: Indicated #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-7) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:3bfa7d75f46e61e2bd95 - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 22860000 - Grade: 0.43 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Indicated resource for disseminated heap leach material includes a silver grade, contributing to the overall project value with high geological confidence. - Positive factor: High confidence resource category \(Indicated\). - Positive factor: Low cutoff grade suitable for heap leach processing. Evidence · table > 0.43 Context: Indicated #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-8) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:5c9344bc9fe8a67e6eec - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: inferred - Tonnes: 1480000 - Grade: 0.83 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Inferred resource for YellowJacket milling material, while having a good gold grade, carries lower geological confidence and is considered speculative. - Positive factor: Good gold grade for an open pit resource. - Negative factor: Lower confidence resource category \(Inferred\). Evidence · table > 1.48 Context: Inferred #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-9) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:5c9344bc9fe8a67e6eec - Deposit or zone: YellowJacket - Mining method: open\_pit - Material type: milling - Ownership percent: 100 % #### Resource Data - Category: inferred - Tonnes: 1480000 - Grade: 4.26 - Grade Unit: g/t - Cutoff Grade: 0.52 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This Inferred resource for YellowJacket milling material includes a silver grade, but carries lower geological confidence and is considered speculative. - Negative factor: Lower confidence resource category \(Inferred\). Evidence · table > 4.26 Context: Inferred #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-10) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:1a5cc5ce0a7df38c05c2 - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: inferred - Tonnes: 176350000 - Grade: 0.19 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This large Inferred resource for disseminated heap leach material, while low grade, offers bulk tonnage potential but carries lower geological confidence. - Positive factor: Large tonnage for heap leach processing. - Positive factor: Low cutoff grade suitable for heap leach operations. - Negative factor: Lower confidence resource category \(Inferred\). Evidence · table > 176.35 Context: Inferred #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-11) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:1a5cc5ce0a7df38c05c2 - Deposit or zone: Disseminated - Mining method: open\_pit - Material type: heap leach - Ownership percent: 100 % #### Resource Data - Category: inferred - Tonnes: 176350000 - Grade: 0.67 - Grade Unit: g/t - Cutoff Grade: 0.15 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: This large Inferred resource for disseminated heap leach material includes a silver grade, but carries lower geological confidence and is considered speculative. - Positive factor: Large tonnage for heap leach processing. - Negative factor: Lower confidence resource category \(Inferred\). Evidence · table > 0.67 Context: Inferred #### 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 **No Contained Metal** Polarity: negative Definition: Tonnage and grade reported but contained metal not calculated or disclosed — incomplete reporting. Why it applies: contained\_metal was not reported **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-12) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:40beba5904f00172cc24 - Deposit or zone: North Bullfrog Project - Mining method: open\_pit - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 28820000 - Contained Metal: 627.7 - Contained Unit: koz #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The total Measured and Indicated resource for gold represents a substantial and high-confidence portion of the project's overall gold endowment. - Positive factor: Significant contained gold in the Measured and Indicated categories. - Positive factor: High confidence resource categories. Evidence · table > 627.7 Context: Total M & I #### 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 **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-resource-facts-13) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Resource scope - Estimate type: resource - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Jeffrey A. Pontius, Carl E. Brechtel, Scott E. Wilson - Resource group id: resource:40beba5904f00172cc24 - Deposit or zone: North Bullfrog Project - Mining method: open\_pit - Ownership percent: 100 % #### Resource Data - Category: indicated - Tonnes: 28820000 - Contained Metal: 3382.6 - Contained Unit: koz #### Prior Estimate - Resource Date: 2015-06-16 #### Lab - Laboratory: ALS Chemex #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The total Measured and Indicated resource for silver represents a substantial and high-confidence portion of the project's overall silver endowment. - Positive factor: Significant contained silver in the Measured and Indicated categories. - Positive factor: High confidence resource categories. Evidence · table > 3,382.6 Context: Total M & I #### 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 **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ## Metallurgical Results (4) ### Fact 1 [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-metallurgical-facts-14) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Test Work - Program Status: detailed - Processing Route: gravity-cyanide leach mill - Sample: YellowJacket mineralization - Grind P80: 74 µm #### Recovery - Recovery: 86.8 % - Recovery Basis: actual\_test #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The high gold recovery of 86.8% from mill processing for YellowJacket mineralization is a strong positive, supported by detailed bench-scale testwork on multiple composites. - Positive factor: High gold recovery for mill processing, indicating efficient extraction. - Positive factor: Multi-domain variability tested with composite samples. - Negative factor: Test scale is bench-scale \(composite samples, PQ core\) rather than pilot scale. Evidence · table > 86.8% Context: Average Gold Recovery - Mill #### Tags used in scoring **Gravity Route** Polarity: neutral Definition: Gravity separation forms a material part of the flowsheet. Why it applies: processing\_route matches the gravity signal ### column leach [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-metallurgical-facts-15) North Bullfrog Project · gold #### Identity - Project: North Bullfrog Project - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Test Work - Program Status: detailed - Test Type: column leach - Processing Route: heap leach - Sample: low grade mineralized material from the Sierra Blanca, Jolly Jane, and Mayflower mineral resources - Grind P80: 84000 µm - Leach Time: 24000 hours #### Recovery - Recovery: 73.9 % - Recovery Basis: actual\_test #### Lab - Laboratory: McClelland Laboratories #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The 73.9% gold recovery from heap leach processing is a good result for this method, supported by extensive column leach testwork from McClelland Laboratories. - Positive factor: Good gold recovery for heap leach processing, which typically has lower recoveries. - Positive factor: Testwork conducted by an independent laboratory \(McClelland Laboratories\). - Positive factor: Multi-domain variability tested with 23 column leach tests. - Negative factor: Test scale is bench-scale \(column leach\) rather than pilot scale. Evidence · table > 73.9% Context: Average Gold Recovery – Heap Leach #### Tags used in scoring **Heap Leach Route** Polarity: neutral Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected. Why it applies: processing\_route matches the heap\_leach signal ### Fact 3 [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-metallurgical-facts-16) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Test Work - Program Status: detailed - Processing Route: gravity-cyanide leach mill - Sample: YellowJacket mineralization - Grind P80: 74 µm #### Recovery - Recovery: 71.4 % - Recovery Basis: actual\_test #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The 71.4% silver recovery from mill processing for YellowJacket mineralization is a good result, contributing to the project's overall economics. - Positive factor: Good silver recovery for mill processing. - Negative factor: Test scale is bench-scale \(composite samples, PQ core\) rather than pilot scale. Evidence · table > 71.4% Context: Average Silver Recovery - Mill #### Tags used in scoring **Gravity Route** Polarity: neutral Definition: Gravity separation forms a material part of the flowsheet. Why it applies: processing\_route matches the gravity signal **Low Recovery** Polarity: negative Definition: Recovery below the weak band for the commodity and processing route. Why it applies: 71.4% is below the weak band \(75%\) ### column leach [Link to this fact](https://atlas-extractions.minestarters.com/news/corvus-gold-files-ni-43-101-technical-report-and-preliminary-economic-assessment--cbc116a1-4c38-4b66-8eae-cdc072f8a02f#fact-metallurgical-facts-17) North Bullfrog Project · silver #### Identity - Project: North Bullfrog Project - Commodity: silver - Region: usa\_nv - Reported Region: Nevada - Ticker: KOR #### Test Work - Program Status: detailed - Test Type: column leach - Processing Route: heap leach - Sample: low grade mineralized material from the Sierra Blanca, Jolly Jane, and Mayflower mineral resources - Grind P80: 84000 µm - Leach Time: 24000 hours #### Recovery - Recovery: 6 % - Recovery Basis: actual\_test #### Lab - Laboratory: McClelland Laboratories #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2015-08-04T00:00:00.000Z Reasoning: The extremely low 6% silver recovery from heap leach processing is a significant negative, suggesting that silver will not be a material byproduct from this processing route. - Negative factor: Very low silver recovery for heap leach processing, indicating poor extractability for silver via this method. - Negative factor: Test scale is bench-scale \(column leach\) rather than pilot scale. Evidence · table > 6% Context: Average Silver Recovery – Heap Leach #### Tags used in scoring **Heap Leach Route** Polarity: neutral Definition: Processing via heap leach — lower CAPEX and OPEX, lower recovery expected. Why it applies: processing\_route matches the heap\_leach signal **Low Recovery** Polarity: negative Definition: Recovery below the weak band for the commodity and processing route. Why it applies: 6% is below the weak band \(75%\) ## 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.