We recognize an estimated liability for future costs associated with the abandonment and reclamation of our mining properties. A liability for the fair value of an asset retirement obligation and a corresponding increase to the carrying value of the related long-lived asset are recorded as the mining operations occur or the assets are acquired.

Our asset retirement obligation is based on the estimated cost to close and reclaim the mining operations, the economic life of the properties, and federal and state regulatory requirements. The liability is discounted using credit adjusted risk-free rate estimates at the time the liability is incurred or when there are upward revisions to estimated costs. The credit adjusted risk-free rates used to discount our reclamation liabilities range from 6.9% to 12.0%. Revisions to the liability occur due to construction of new or expanded facilities, changes in estimated closure costs or economic lives, or to reflect new federal or state rules, regulations, or requirements regarding the closure or reclamation of mines.


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Asset retirement obligation, at beginning of period	$	39,228	$	33,241	$	38,452	$	32,592
Liabilities settled	(75)		—		(75)		—


Accretion of discount	777		650		1,553		1,299
Total asset retirement obligation, at end of period	$	39,930	$	33,891	$	39,930	$	33,891
Less current portion of asset retirement obligation	$	—	$	(595)	$	—	$	(595)
Long-term portion of asset retirement obligation	$	39,930	$	33,296	$	39,930	$	33,296

The current portion of the asset retirement obligation, if any, is included in "Other current liabilities" on the Condensed Consolidated Balance Sheet as of June 30, 2026, and December 31, 2025.