Reclamation and Mine Closure

3 Months Ended

Mar. 31, 2012

Asset Retirement Obligation Disclosure [Abstract]

Asset retirement obligation

RECLAMATION AND MINE CLOSURE

Reclamation and mine closure costs are based principally on legal and regulatory requirements. Management estimates costs associated with reclamation of mining properties as well as remediation costs for inactive properties. The Company uses assumptions about future costs, mineral prices, mineral processing recovery rates, production levels, capital costs and reclamation costs. Such assumptions are based on the Company’s current mining plan and the best available information for making such estimates. On an ongoing basis, management evaluates its estimates and assumptions; however, actual amounts could differ from those based on such estimates and assumptions.

Changes to the Company’s asset retirement obligations are as follows (in thousands):

	Three months ended March 31,
	2012			2011
Asset retirement obligation - Beginning	$	32,714		$	27,302
Accretion	724			637
Addition and changes in estimates	—			—
Settlements	(4		)	(31		)
Asset retirement obligation - March 31	$	33,434		$	27,908

In addition, the Company has accrued $1.0 million and $1.0 million as of March 31, 2012 and December 31, 2011, respectively, for reclamation liabilities related to former mining activities. These amounts are also included in reclamation and mine closure liabilities.