CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Cash and cash equivalents	$ 57,566	$ 106,210
Prepaids and deposits – Note 3	3,993	3,326
Supplies inventories, net – Note 4	1,709	1,834
Income tax receivable	1,530	1,530
Interest receivable	466	667
Other receivable	200	0
Current assets	65,464	113,567
Property, plant, and equipment, net – Note 5	52,093	53,091
Restricted cash – Note 6	26,633	26,340
Assets held for sale – Note 7	7,148	7,148
Prepaids – Note 3	1,231	1,547
Total assets	152,569	201,693
Liabilities:
Asset retirement obligation	3,517	3,172
Accounts payable and accrued expenses – Note 8	1,690	1,631
Debt, net – Notes 9 and 21	130	2,330
Contract liabilities – Note 10	109	1,550
Other liabilities – Note 11	568	3,063
Current liabilities	6,014	11,746
Debt, net – Notes 9 and 21	116,410	142,617
Deferred gain on sale of royalty	29,839	29,839
Asset retirement obligation – Note 12	6,540	4,801
Warrant liabilities – Notes 13 and 20	21	26
Other liabilities – Note 11	0	8
Total liabilities	158,824	189,037
Commitments and contingencies – Note 23
Stockholders’ equity – Note 14
Common stock, $0.0001 par value; 1,400,000,000 shares authorized; 21,256,895 issued and outstanding at March 31, 2024, and 20,736,612 issued and outstanding at December 31, 2023, respectively	21	21
Additional paid-in capital	739,648	737,810
Accumulated deficit	(745,924)	(725,175)
Total stockholders’ (deficit) equity	(6,255)	12,656
Total liabilities and stockholders’ equity	$ 152,569	$ 201,693