UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows used in operating activities:
Net loss	$ (20,749)	$ (13,909)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Accelerated amortization of original issue discount and issuance costs – Note 9	6,871	0
Non-cash portion of interest expense – Note 9	2,744	2,963
Asset retirement obligation adjustments – Note 12	1,991	0
Stock-based compensation – Note 15	679	608
Depreciation and amortization – Notes 2 and 5	616	718
Accretion – Note 12	232	186
Loss on sale of equipment, net of commissions	132	0
Write-down of supplies inventories	12	0
Non-cash lease expense		0
Non-cash lease expense	(2)
(Gain) on fair value adjustment for warrant liabilities – Notes 13 and 20	(5)	(122)
Gain on non-refundable deposit - Note 19	(1,441)	0
Changes in operating assets and liabilities:
Interest receivable	201	(53)
Supplies inventories, net – Note 4	113	62
Accounts payable and accrued expenses – Note 8	59	(1,082)
Other receivable	(200)	2,771
Prepaids – Note 3	(351)	792
Other liabilities – Note 11	(2,635)	(1,752)
Net cash used in operating activities	(11,733)	(8,818)
Cash flows provided by (used in) investing activities:
Proceeds from sale of equipment	270	0
Additions to property, plant, and equipment	(25)	(271)
Net cash provided by (used in) by investing activities	245	(271)
Cash flows provided by (used in) financing activities:
Proceeds from issuance of common stock, net of issuance costs – Note 14	1,160	0
Principal payments on notes payable	(32)	(32)
Principal payments on debt - Note 9	(37,991)	(550)
Net cash used in financing activities	(36,863)	(582)
Net decrease in cash, cash equivalents, and restricted cash	(48,351)	(9,671)
Cash, cash equivalents, and restricted cash, beginning of period	132,550	175,966
Cash, cash equivalents, and restricted cash, end of period	84,199	166,295
Reconciliation of cash, cash equivalents, and restricted cash:
Cash and cash equivalents	57,566	131,987
Restricted cash	26,633	34,308
Total cash, cash equivalents, and restricted cash	$ 84,199	$ 166,295