Asset Retirement Obligation

6 Months Ended

Jun. 30, 2011

12. ASSET RETIREMENT OBLIGATION

The following table provides a rollforward of the asset retirement obligation. Liabilities settled include settlement payments for obligations as well as obligations that were assumed by the purchasers of divested properties. Liabilities incurred include additions to obligations as well as obligations that were assumed by the Company related to acquired properties. Activity related to the Company's asset retirement obligation is as follows:


(In thousands)
Carrying amount of asset retirement obligations at December 31, 2010	$	72,311
Liabilities added during the current period		617
Liabilities settled and divested during the current period		(610	)
Current period accretion expense		1,730

Carrying amount of asset retirement obligations at June 30, 2011	$	74,048