Asset Retirement Obligation

12 Months Ended

Dec. 31, 2016

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligation

7. ASSET RETIREMENT OBLIGATION

The Company’s mining and exploration activities are subject to various state and federal law and regulations governing the protection of the environment. The Company conducts its operations to protect public health and the environment and believes its operations are in compliance with the applicable laws and regulations in all material respects. The Company has made, and expects to make in the future, expenditures to comply with such laws and regulations, but cannot predict the full amount of such future expenditures. Estimated future restoration and reclamation costs are based principally on legal and regulatory requirements.

Changes to the Company’s asset retirement obligation are summarized below:

	December 31,	December 31,
	2016	2015
	(thousands of dollars)
Balance, beginning  of period	$              4,468	$         4,196
Liabilities settled	(54)	(178)
Accretion expense	480	450
Balance, end of period	4,894	4,468
Less:  Included in liabilities held for sale	(105)	(105)
Less:  Current portion	(121)	(121)
Non-current portion	$              4,668	$         4,242

As of December 31, 2016, the Company’s asset retirement obligation was fully secured by surety bonds totaling $9.2 million, which were partially collateralized with restricted cash totaling $4.0 million.