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SHAREHOLDERS' EQUITY (Details) - USD ($) |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Feb. 09, 2021 | Jan. 29, 2021 | Dec. 31, 2020 | Sep. 10, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020 | Jun. 30, 2021 | Jun. 29, 2021
Common stock, shares authorized |  |  |  |  |  |  |  |  |  | 675,000,000 | 500,000,000
Net proceeds |  |  |  |  |  |  | $ 29,875,000 |  |  |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  |  |  | 29,875,000 |  |  |  |
November 2019 Offering |  |  |  |  |  |  |  |  |  |  |
Outstanding warrants |  |  |  |  | $ 21,706,250 |  | 21,706,250 |  |  |  |
March 2019 Offering |  |  |  |  |  |  |  |  |  |  |
Outstanding warrants |  |  |  |  | 8,064,516 |  | 8,064,516 |  |  |  |
Canadian Exploration Expenditures |  |  |  |  |  |  |  |  |  |  |
Gross proceeds |  |  |  |  |  |  |  |  | $ 20,200,000 |  |
Equity Financing In February 2021 |  |  |  |  |  |  |  |  |  |  |
Number of units issued | 30,000,000 |  |  |  |  |  |  |  |  |  |
Price per unit | $ 1.05 |  |  |  |  |  |  |  |  |  |
Gross proceeds | $ 31,500,000 |  |  |  |  |  | $ 31,500,000 |  |  |  |
Net proceeds | 29,900,000 |  |  |  |  |  |  |  |  |  |
Issuance costs | $ 1,700,000 |  |  |  |  |  |  |  |  |  |
Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  |  |  | 30,000,000 |  |  |  |
Net proceeds |  |  |  |  |  |  | $ 29,875,000 |  |  |  |
Shares issued for acquisition of mineral property interests (in shares) |  |  |  |  |  | 53,000 |  | 53,000 |  |  |
Flow Through Common Shares | Canadian Development Expenses |  |  |  |  |  |  |  |  |  |  |
Number of units issued |  | 12,600,600 |  |  |  |  |  |  |  |  |
Price per unit |  | $ 1.01 |  |  |  |  |  |  |  |  |
Gross proceeds |  | $ 12,700,000 |  |  |  |  | 12,700,000 |  |  |  |
Net proceeds |  | 12,000,000.0 |  |  |  |  |  |  |  |  |
Issuance costs |  | 700,000 |  |  |  |  |  |  |  |  |
Net proceeds allocated to the sale of tax benefits |  | 1,200,000 |  |  |  |  |  |  |  |  |
Sale of common stock for cash, net of issuance costs |  | $ 10,800,000 |  |  |  |  |  |  |  |  |
Flow Through Common Shares | Canadian Exploration Expenditures |  |  |  |  |  |  |  |  |  |  |
Number of units issued |  |  | 7,669,900 | 6,298,166 |  |  |  |  |  |  |
Price per unit |  |  | $ 1.28 | $ 1.65 |  |  |  |  | $ 1.28 |  |
Gross proceeds |  |  | $ 9,800,000 | $ 10,400,000 |  |  |  |  |  |  |
Net proceeds |  |  | 9,800,000 | 9,800,000 |  |  |  |  |  |  |
Issuance costs |  |  | 0 | 600,000 |  |  |  |  |  |  |
Net proceeds allocated to the sale of tax benefits |  |  | 2,100,000 | 2,000,000.0 |  |  |  |  |  |  |
Sale of common stock for cash, net of issuance costs |  |  | $ 7,700,000 | $ 7,800,000 |  |  |  |  |  |  |
Exploration expenditures |  |  |  |  | $ 9,300,000 |  | $ 11,200,000 |  | $ 1,900,000 |  |

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