Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 4,054	$ 3,309
Marketable securities	1,361
Notes receivable - current	1,750
Prepaid and other current assets	668	602
Total Current Assets	7,833	3,911
Property, plant and equipment, at cost:
Property, plant and equipment	101,187	112,964
Less accumulated depreciation and depletion	(65,778)	(66,048)
Net property, plant and equipment	35,409	46,916
Restricted cash	3,668	3,964
Notes receivable, non-current	3,328
Long-term assets held for sale		2,123
Total Assets	50,238	56,914
Current Liabilities:
Accounts payable	538	610
Accrued liabilities	2,352	1,981
Convertible loan net of discount		5,431
Current portion of asset retirement obligations	1,078	121
Total Current Liabilities	3,968	8,143
Asset retirement obligations, net of current portion	4,653	4,668
Other long-term liabilities	500	500
Long-term liabilities related to assets held for sale		555
Total Liabilities	9,121	13,866
Commitments and Contingencies
Stockholders' Equity:
Common stock, 100,000,000 shares authorized, $.001 par value; Issued shares - 27,790,324 and 16,675,419, respectively Outstanding shares - 27,782,299 and 16,667,394, respectively	28	17
Paid-in capital	297,250	280,191
Accumulated other comprehensive gain	287
Accumulated deficit	(256,190)	(236,902)
Less: Treasury stock (8,025 and 8,025 shares, respectively), at cost	(258)	(258)
Total Stockholders' Equity	41,117	43,048
Total Liabilities and Stockholders' Equity	$ 50,238	$ 56,914

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).