Unaudited Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 5,911,310	$ 5,934,043
Short-term investments		5,199,861
Accounts receivable	28,265,692	7,165,487
Inventories	11,294,596	10,057,787
Prepaid expenses	2,870,297	1,104,437
Total current assets	48,341,895	29,461,615
Property, plant and equipment, net	136,574,558	115,450,841
Advanced coal royalties	2,785,748	2,867,369
Other assets	524,648	318,206
Total Assets	188,226,849	148,098,031
Current liabilities
Accounts payable	20,062,221	19,532,531
Accrued expenses	8,824,787	2,821,422
Asset retirement obligations	512,997	70,616
Notes payable, net	14,758,593
Other	361,918
Total current liabilities	44,520,516	22,424,569
Deferred tax liability	1,385,717
Asset retirement obligations	12,208,126	12,276,176
Total liabilities	58,114,359	34,700,745
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	400,825	395,594
Additional paid-in capital	149,533,523	148,293,263
Accumulated deficit	(19,821,858)	(35,291,571)
Total stockholders' equity	130,112,490	113,397,286
Total Liabilities and Stockholders' Equity	$ 188,226,849	$ 148,098,031