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SHAREHOLDERS' EQUITY (Details) - USD ($) |  |  |  |  |  |  |  | 3 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | ---
Feb. 09, 2021 | Jan. 29, 2021 | Dec. 31, 2020 | Sep. 10, 2020 | Nov. 20, 2019 | May 23, 2019 | Mar. 29, 2019 | Mar. 31, 2021 | Jun. 30, 2020
Number of units issued |  |  |  |  |  | 1,935,484 |  |  |
Net proceeds |  |  |  |  |  | $ 2,600,000 |  | $ 29,875,000 |
Issuance costs |  |  |  |  |  | $ 400,000 |  |  |
Sale of common stock for cash, net of issuance costs |  |  |  |  |  |  |  | 29,875,000 |
November 2019 Offering |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  | 37,750,000 |  |  |  |
Price per unit |  |  |  |  | $ 1.325 |  |  |  |
Gross proceeds |  |  |  |  | $ 46,600,000 |  |  |  |
Net proceeds |  |  |  |  | $ 46,600,000 |  |  |  |
Warrant expiration term |  |  |  |  | 5 years |  |  |  |
Issuance costs |  |  |  |  | $ 3,500,000 |  |  |  |
Outstanding warrants |  |  |  |  |  |  |  | 21,706,250 |
Warrants issued in connection with equity issuance |  |  |  |  | 2,831,250 |  |  |  |
June 2020 Amended and Restated Credit Agreement |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  |  |  |  |  | 2,091,700
Net proceeds |  |  |  |  |  |  |  |  | $ 1,900,000
March 2019 Offering |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  |  |  | 14,193,548 |  |
Price per unit |  |  |  |  |  |  | $ 1.55 |  |
Net proceeds |  |  |  |  |  |  | $ 20,300,000 |  |
Number of shares of common stock |  |  |  |  |  |  | 1 |  |
Number of warrants received for each share of common stock share sold |  |  |  |  |  |  | 0.50 |  |
Issuance costs |  |  |  |  |  |  | $ 1,700,000 |  |
Outstanding warrants |  |  |  |  |  |  |  | 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 |  |  |  |  |  |  |  |
Net proceeds | 29,900,000 |  |  |  |  |  |  |  |
Issuance costs | $ 1,700,000 |  |  |  |  |  |  |  |
Subscription Receipts | Officers Directors And Certain Employees |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  |  |  | 1,935,484 |  |
Price per unit |  |  |  |  |  |  | $ 1.55 |  |
Common Stock and Additional Paid-in Capital |  |  |  |  |  |  |  |  |
Number of units issued |  |  |  |  |  |  |  | 30,000,000 |
Net proceeds |  |  |  |  |  |  |  | $ 29,875,000 |
Common Stock and Additional Paid-in Capital | November 2019 Offering |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  | 37,300,000 |  |  |  |
Warrant at First Stock Price | November 2019 Offering |  |  |  |  |  |  |  |  |
Net proceeds |  |  |  |  | $ 9,300,000 |  |  |  |
Number of shares of common stock |  |  |  |  | 1 |  |  |  |
Number of warrants received for each share of common stock share sold |  |  |  |  | 0.50 |  |  |  |
Warrant at First Stock Price | March 2019 Offering |  |  |  |  |  |  |  |  |
Number of shares of common stock |  |  |  |  |  |  | 1 |  |
Price per common share for each warrant |  |  |  |  |  |  | $ 2.00 |  |
Warrant expiration term |  |  |  |  |  |  | 3 years |  |
Warrant at Second Stock Price | November 2019 Offering |  |  |  |  |  |  |  |  |
Number of shares of common stock |  |  |  |  | 1 |  |  |  |
Price per common share for each warrant |  |  |  |  | $ 1.7225 |  |  |  |
Flow Through Common Shares | Canadian Development Expenses |  |  |  |  |  |  |  |  |
Number of units issued |  | 12,600,600 |  |  |  |  |  |  |
Price per unit |  | $ 1.01 |  |  |  |  |  |  |
Gross proceeds |  | $ 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 |  |  |  |  |  |  |
Exploration expenditures |  |  |  |  |  |  |  | 7,900,000 |
Flow Through Common Shares | Canadian Exploration Expenditures |  |  |  |  |  |  |  |  |
Number of units issued |  |  | 7,669,900 | 6,298,166 |  |  |  |  |
Price per unit |  |  | $ 1.28 | $ 1.65 |  |  |  |  |
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 |  |  |  |  |  |  |  | $ 4,300,000 |

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