The U.S. Department of the Interior has offered 918,000 acres of leases to oil and gas operations in areas designated for priority big game, a new analysis found.

Rocky Mountain Wild, a Denver-based advocacy group for protecting the biodiversity of the Rocky Mountain region, looked at winter range and migration corridors for big game from various state agencies, and parcels of land identified for sale from the U.S. Bureau of Land Management.

“We urge the Department of the Interior to minimize energy leasing and development of federal minerals in the priority areas or priority landscapes defined by the states in the Action Plans created in response to Secretarial Order 3362,” the group wrote in its findings.

In 2018, then-Interior Secretary Ryan Zinke issued the order directing agencies to develop action plans with each Western state in the continental U.S. One task was to develop “habitat management goals” for big game. The agencies would then use the plans to “evaluate how land under each bureau’s management responsibility can contribute to State or other efforts to improve the quality and condition of priority big-game winter and migration corridor habitat.”

The report noted that oil and gas operations are disruptive to the habitats of mule deer, which avoid the extraction areas and alter their migratory patterns.

In Colorado, Interior attempted to offer 91,700 acres of priority lands for oil and gas drilling, and ended up offering 40,500 acres. Of the six states analyzed, Wyoming by far had the largest number of acres leased in big game priority areas, with 664,000 acres eventually offered between November 2018 and December 2019.

“While Secretary [David] Bernhardt publicly states that protecting migration corridors for future generations is a priority, his policies show that is not the case,” said Tehri Parker, executive director of Rocky Mountain Wild.

An Interior Department spokesperson called the report “completely erroneous” and with “numerous inaccuracies. The truth is, the Department is working with the states to ensure they have the support and financial means to develop scientifically defined migration corridors. We are making great strides and accomplishing meaningful habitat conservation for big game species.”

Editor’s note: This story has been updated with comment from the Department of the Interior.