SEGMENTED INFORMATION - Operations for Reportable Segments (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2025 USD ($) segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment	4
Number of reportable segments | segment	4
Segment Reporting Information [Line Items]
Revenue	$ 14,048	$ 8,413
Pre-development, evaluation and exploration	(9,545)	(7,274)
Property maintenance	(4,147)	(4,322)
Adjusted loss from operations	(9,868)	(10,254)
Depletion, depreciation and amortization	(376)	(377)
Royalties	(542)	(1,261)
General and administrative	(4,990)	(4,225)
Loss from operations	(15,776)	(16,117)
Capital expenditures	633		$ 2,307
Total assets	658,968		655,629
Operating Segments | Granite Creek
Segment Reporting Information [Line Items]
Revenue	8,695	3,198
Costs applicable to sales	(8,318)	(4,905)
Pre-development, evaluation and exploration	(3,770)	(4,480)
Property maintenance	(145)	(234)
Adjusted loss from operations	(3,538)	(6,421)
Capital expenditures	378		1,138
Total assets	118,897		115,414
Operating Segments | Ruby Hill
Segment Reporting Information [Line Items]
Revenue	1,390	913
Costs applicable to sales	(1,082)	(870)
Pre-development, evaluation and exploration	(3,191)	(416)
Property maintenance	(837)	(498)
Adjusted loss from operations	(3,720)	(871)
Capital expenditures	192		407
Total assets	118,707		117,277
Operating Segments | Lone Tree
Segment Reporting Information [Line Items]
Revenue	3,963	4,302
Costs applicable to sales	(824)	(1,296)
Pre-development, evaluation and exploration	(23)	(9)
Property maintenance	(2,747)	(3,193)
Adjusted loss from operations	369	(196)
Capital expenditures	63		762
Total assets	262,075		259,689
Operating Segments | Cove
Segment Reporting Information [Line Items]
Revenue	0	0
Costs applicable to sales	0	0
Pre-development, evaluation and exploration	(2,547)	(2,272)
Property maintenance	(215)	(253)
Adjusted loss from operations	(2,762)	(2,525)
Capital expenditures	0		0
Total assets	53,122		53,412
Corporate and other
Segment Reporting Information [Line Items]
Revenue	0	0
Costs applicable to sales	0	0
Pre-development, evaluation and exploration	(14)	(97)
Property maintenance	(203)	(144)
Adjusted loss from operations	(217)	$ (241)
Capital expenditures	0		0
Total assets	$ 106,167		$ 109,837