Three Denver-based environmental groups are suing the U.S. Department of Agriculture’s Wildlife Services branch, challenging two plans approved by Colorado Parks and Wildlife that together would kill up to 120 mountain lions and bears to protect declining mule deer populations.

The Center for Biological Diversity, WildEarth Guardians and the Western Environmental Law Center allege that two Predator Management plans did not receive the proper environmental-impact assessments and relied upon “unsound” science in blaming predators — not oil and gas development — for Colorado’s loss of mule deer.

“We aren’t seeing a lot of scientific support for it in the literature,” says Matthew Bishop, an attorney at the Western Environmental Law Center representing the conservation groups. “What we do have, which we consider to be the best available science, suggests that it’s loss of habitat that’s really the driving factor.”

The lawsuit aims to hold accountable the USDA’s Wildlife Services branch, which provides funding to CPW and may also carry out the management plans. The question is whether the federal agency, which is bound by higher environmental laws than the state's, skirted the proper environmental assessment in approving the plan.

Specifically, Bishop believes that Wildlife Services failed to comply with the National Environmental Policy Act, which requires that federal agencies provide detailed assessments of how a policy will impact the environment.

Wildlife Services did not respond to Westword’s requests for a comment on the lawsuit or the approved management plans. Colorado Parks and Wildlife does not comment on ongoing litigation, a spokesperson says, but it is working to address the public’s concerns.

The plans authorize the deaths of up to 45 mountain lions and 75 bears over three years in the Upper Arkansas River basin, near Leadville, and in the Piceance Basin near Gunnison, Grand Junction and Rifle. Wildlife Services will use traps to immobilize the animals before killing them with poison or bullets. The suit has implications beyond these two management plans, challenging Wildlife Services’ entire Predator Damage Management in Colorado.

“The proposal on those two plans is to really focus on black bears and mountain lions,” says Bishop. “But the lawsuit itself actually targets the program statewide, and that includes bobcats and other carnivores.”

Central to conservationists’ concerns are disagreements in the scientific community about the causes of the mule deer decline. Whereas CPW blames predation, the conservation groups argue that human-driven activities such as oil and gas development, mining and suburban expansion are to blame.

In a 2008 testimonial before the Colorado Oil and Gas Conservation Commission, which regulates oil and gas development, five top CPW scientists acknowledged that “oil and gas development may reduce the quantity of habitats, degrade the quality of habitats, or make portions of key habitats unavailable to mule deer because of behavioral avoidance.”

The Piceance Basin has seen high levels of natural-gas extraction relative to the rest of the state. Garfield County, which includes the towns of Rifle and Battlement Mesa, has the highest level of natural-gas production in Colorado. In 2016, the U.S. Geological Survey called the Piceance Basin “the second-largest assessment of potential continuous gas resources that the USGS has ever conducted.”

Mule deer are valuable to the state’s economy and government. In 2002, deer hunting indirectly brought $97.5 million to Colorado while providing an average of almost $14 million per year to CPW between 1982 and 2006 when adjusted for inflation. In 2015, hunting licenses provided 62 percent of CPW revenue from its entire wildlife management.

