Annual report pursuant to Section 13 and 15(d)

Mineral Properties (Details)

v3.20.4
Mineral Properties (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Balance at beginning of period $ 43,212,000 $ 45,805,000 $ 44,677,000
Change in estimated reclamation costs (1,583,000) 11,000 2,840,000
Acquisition costs   8,000 31,000
Depletion and amortization (2,445,000) (2,601,000) (1,743,000)
Property write-offs   (11,000)  
Balance at end of period 39,184,000 43,212,000 45,805,000
Lost Creek Property [Member]      
Balance at beginning of period 10,184,000 12,644,000 11,810,000
Change in estimated reclamation costs (1,463,000) 125,000 2,577,000
Acquisition costs   0 0
Depletion and amortization (2,445,000) (2,601,000) (1,743,000)
Property write-offs   16,000  
Balance at end of period 6,276,000 10,184,000 12,644,000
Pathfinder Properties [Member]      
Balance at beginning of period 19,850,000 19,964,000 19,701,000
Change in estimated reclamation costs (120,000) (114,000) 263,000
Acquisition costs   0 0
Depletion and amortization 0 0 0
Property write-offs   0  
Balance at end of period 19,730,000 19,850,000 19,964,000
Other U.S. Properties [Member]      
Balance at beginning of period 13,178,000 13,197,000 13,166,000
Change in estimated reclamation costs 0 0 0
Acquisition costs   8,000 31,000
Depletion and amortization 0 0 0
Property write-offs   (27,000)  
Balance at end of period $ 13,178,000 $ 13,178,000 $ 13,197,000