Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 6,951	$ 5,934
Short-term investments		5,200
Accounts receivable	10,729	7,166
Inventories	14,185	10,058
Prepaid expenses	3,154	1,104
Total current assets	35,019	29,462
Property, plant and equipment – net	149,205	115,451
Advanced coal royalties	3,045	2,867
Other	975	318
Total Assets	188,244	148,098
Current liabilities
Accounts payable	16,393	19,533
Accrued expenses	8,094	2,821
Asset retirement obligations	71	71
Current portion of long-term debt	5,000
Financed insurance payable	287
Total current liabilities	29,845	22,425
Asset retirement obligations	12,707	12,276
Long-term debt	4,474
Deferred tax liability	109
Total liabilities	47,135	34,701
Commitments and contingencies
Stockholders' Equity
Preferred stock, $0.01 par value, 50,000,000 shares authorized, none issued and outstanding
Common stock, $0.01 par value, 260,000,000 shares authorized, 40,082,467 and 39,559,366 shares issued and outstanding, respectively	401	396
Additional paid-in capital	150,926	148,293
Accumulated deficit	(10,218)	(35,292)
Total equity	141,109	113,397
Total Liabilities and Stockholders' Equity	$ 188,244	$ 148,098