RECLAMATION

Reclamation and mine closure costs are based principally on legal and regulatory requirements. Management estimates costs associated with reclamation of mining properties. The Company uses assumptions about future costs, mineral prices, mineral processing recovery rates, production levels, capital costs, and reclamation costs. On an ongoing basis, management evaluates its estimates and assumptions, and future expenditures could differ from current estimates.

Changes to the Company’s asset retirement obligations for operating sites (included in Reclamation) are as follows:



	Three months ended March 31,
In thousands	2015			2014
Asset retirement obligation - Beginning	$	67,214		$	57,454
Accretion	1,412			1,317
Additions and changes in estimates	18,292			—
Settlements	(859		)	(311		)
Asset retirement obligation - Ending	$	86,059		$	58,460

The increase in asset retirement obligations in the three months ended March 31, 2015 is due to the acquisition of the Wharf gold mine. The Company has accrued $3.7 million and $3.6 million at March 31, 2015 and December 31, 2014, respectively, for reclamation liabilities related to former mining activities. These amounts are also included in Reclamation.