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MINERAL PROPERTY INTERESTS AND PLANT AND EQUIPMENT | 9 Months Ended
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Sep. 30, 2020
MINERAL PROPERTY INTERESTS AND PLANT AND EQUIPMENT |
MINERAL PROPERTY INTERESTS AND PLANT AND EQUIPMENT | NOTE 9 MINERAL PROPERTY INTERESTS AND PLANT AND EQUIPMENT The definition of proven and probable reserves is set forth in the SEC Industry Guide 7. If proven and probable reserves exist at the Company’s properties, the relevant capitalized mineral property interests and asset retirement costs are charged to expense based on the units of production method upon commencement of production. The Company’s Gold Bar, Black Fox and San José properties have proven and probable reserves estimated in accordance with SEC Industry Guide 7. The Company reviews and evaluates its long-lived assets for impairment on a quarterly basis or when events or changes in circumstances indicate that the related carrying amounts may not be recoverable. Once it is determined that impairment exists, an impairment loss is measured as the amount by which the asset carrying value exceeds its estimated fair value. ​ As part of the analysis conducted in Q1 2020, the Company determined that indicators of impairment existed for the long-lived assets at the Gold Bar mine and that the long-lived assets at the Gold Bar mine were not recoverable on an undiscounted basis. The fair value of the Gold Bar mine was estimated using the discounted cash flow method, coupled with an in-situ resource multiple for mineralized material not included in the life of mine plan. Future cash flows were estimated based on estimated quantities of recoverable mineralized material, expected gold prices, estimated production levels, operating costs, capital requirements and reclamation costs, all based on the life-of-mine plan using the preliminary estimated resources. The in-situ resource multiple applied to the mineralized material not included in the life-of-mine plan was estimated by evaluating observable market transactions. The Company concluded that the carrying value of the long-lived assets at the Gold Bar mine was impaired and recorded a non-cash impairment charge reducing plant and equipment and mineral property interests by the amount of $83.8 million. ​ The following table sets forth a summary of the quantitative and qualitative information related to the unobservable inputs used in the calculation of the Company’s non-recurring Level 3 fair value measurement of the Gold Bar mine: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
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​ | ​ | Date of Fair Value Measurement | ​ | Valuation Technique | ​ | Unobservable Input | ​ | Range/ Weighted Average
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Gold Bar Mine | ​ | March 31, 2020 | ​ | Discounted Cash Flow | ​ | Discount Rate | ​ | 9%
​ | ​ | ​ | ​ | ​ | ​ | Long Term Gold Price | ​ | $1,430/oz
​ | ​ | ​ | ​ | ​ | ​ | United States Inflation Index | ​ | 2%
​ The estimated future cash flows are based on numerous assumptions and uncertainties. It is possible that actual future cash flows will be significantly different than the estimates, as actual future quantities of recoverable minerals, gold prices, production levels and costs of capital are each subject to significant risks and uncertainties.

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