The private coal lease more than triples the company’s available coal resources at Absaloka, near Hardin.

In all, Westmoreland controlled about 389.9Mt of proven and probable reserves company-wide at the end of last year.

“This lease solidifies our position as a key operator in the northern Powder River Basin, extends the mine life at Absaloka, allows for increased production as demand warrants and enables greater mine optimisation,” president and chief executive officer Keith Alessi said.

The company announced a move to its new headquarters in June, going north from Colorado Springs to the Denver suburb of Englewood to provide better visibility with other public mining and energy companies and achieve a lower overall cost of travel, fees and expenses with its Denver-based third-party providers.

“[Englewood provides] us with greater exposure to a broader pool of public company and energy company talent,” Alessi said at the time.

Westmoreland moved its staff last month and has signed a multi-year lease agreement with Shea Properties at the Meridian International Business Centre.

Westmoreland Coal is the oldest independent coal company in the United States.

Its operations are located in the Powder River Basin region in Montana and it also holds lignite mines in Montana, North Dakota and Texas.