CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Cash	$ 36,497	$ 56,363
Accounts receivable	14	426
Inventories - Note 4	18,950	12,867
Ore on leach pads, current - Note 4	33,090	38,041
Prepaids and other - Note 5	4,565	4,303
Current assets	93,116	112,000
Ore on leach pads, non-current - Note 4	9,243	7,243
Other assets, non-current - Note 5	14,488	13,483
Plant, equipment, and mine development, net - Note 6	66,355	60,223
Restricted cash - Note 7	39,700	39,677
Total assets	222,902	232,626
Liabilities:
Accounts payable and accrued expenses	14,990	12,280
Other liabilities, current - Note 8	4,980	4,157
Debt, net, current - Note 9	7,441	5,120
Royalty obligation, current - Note 10	124	124
Current liabilities	27,535	21,681
Other liabilities, non-current - Note 8	1,375	1,650
Warrant liabilities, non-current - Note 11	5,897	15,389
Debt, net, non-current - Note 9	145,844	142,665
Royalty obligation, non-current - Note 10	29,813	29,839
Asset retirement obligation, non-current - Note 12	4,887	4,785
Total liabilities	215,351	216,009
Commitments and contingencies - Note 21
Stockholders' (deficit) equity
Common stock, $0.0001 par value; 400,000,000 shares authorized; 59,901,306 issued and outstanding at March 31, 2021; and 59,901,306 issued and outstanding at December 31, 2020	6	6
Additional paid-in capital	537,992	537,370
Accumulated deficit	(530,447)	(520,759)
Total stockholders' equity	7,551	16,617
Total liabilities and stockholders' equity	$ 222,902	$ 232,626