Federal judge’s ruling ends Colorado’s plan to kill hundreds of mountain lions in Upper Arkansas River Basin

Federal judge’s ruling ends Colorado’s plan to kill hundreds of mountain lions in Upper Arkansas River Basin

A U.S. District Court judge has ruled that federal dollars cannot be used to fund a Colorado Parks and Wildlife plan to kill hundreds of mountain lions in the Upper Arkansas River Valley as part of a study of the impact of predators on declining mule deer populations.

The U.S. Fish and Wildlife Service needed to conduct its own environmental analysis of Colorado’s predator management plan before funding long-term projects that kill bears and cougars, Judge Marcia Krieger ruled last week. She ruled the federal agency should have conducted its own environmental review — not relied on another agency’s study — when it helped pay for the killing of as many as 230 mountain lions between Leadville and Salida as part of a Colorado Parks and Wildlife plan to bolster mule deer herds.

“At least for right now, there is no federal funding for a $4 million project and without the funding, they will not be able to move forward in the same capacity,” said Andrea Zaccardi, an attorney with the Center for Biological Diversity, which sued the U.S. Fish and Wildlife Service in 2018 over its support for Colorado Parks and Wildlife’s plan.

The federal court ruling last week cuts funding for a nine-year project that would remove half of the mountain lions in the Upper Arkansas River Basin. An application for federal funding for the mountain lion reduction in the basin shows costs ranging from $358,000 to $435,000 a year and the state asked the federal government to pay roughly 75% of that cost. A spokeswoman with Fish and Wildlife said the service is aware of the court’s decision “and will be considering the next steps.”

In 2016, Colorado Parks and Wildlife worked with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service on an environmental assessment of Colorado’s predator-management policy. The study concluded in 2017 that the state’s management plan did not require an overhaul or more intensive environmental review. That same year, Colorado Parks and Wildlife proposed a study that would weigh the role of predators on declining mule-deer populations in the Piceance Basin on the Western Slope and the Upper Arkansas River Valley between Leadville and Salida.

Mule deer populations are declining in the Piceance Basin, which is widely considered some of the West’s best habitat for the ungulates. The same is happening in the headwaters of the Arkansas River. Colorado Parks and Wildlife hopes the predator reduction projects will help home in on possible reasons for that decline.

Zaccardi pointed to studies showing that reducing predators does not actually boost mule deer populations. “Predators usually prey on the weakest link in a herd. They are killing the weak, young, sick and old mule deer, which can actually make herds stronger in the long run,” she said.

WildEarth Guardians and the Humane Society joined the Center for Biological Diversity in suing the U.S. Fish and Wildlife Service. The wildlife groups argued several studies showed the predator reduction was “scientifically unsupported” and federal agents used “extremely cruel methods,” like traps, snares and hounds to kill animals.

“The federal government had no business funding this completely unnecessary state-sponsored slaughter,” said Laura Smythe, staff attorney with the Humane Society of the United States, in a statement.

Krieger’s ruling said Fish and Wildlife needed to conduct its own review of the state’s predator management plan, including more study of ”the cumulative effects of the project on cougar cubs orphaned by the killing of their mother.”

Colorado Parks and Wildlife has completed its predator project in the Piceance Basin but isn’t saying how many black bears it trapped, killed or relocated. It’s also not discussing its research into how fewer bears may be influencing mule deer numbers.

It’s hard to track whether the reduction of black bears in the area has led to fewer conflicts with humans. Wildlife officers in 2020 started using an app to better document and track human-bear conflicts. Previous tracking of human-bear conflicts documented only serious interactions, not bears in beehives, bird feeders or chicken coops.

Using the new system, wildlife officers took reports on 1,034 human-bear encounters in 2020 in the area that includes the Piceance Basin, a majority of those involving bears getting into trash.

Colorado Parks and Wildlife counted 4,943 bear-human conflicts in 2020.
Colorado Parks and Wildlife counted 4,943 bear-human conflicts in 2020.

A public records request filed in 2018 by the Center for Biological Diversity yielded a handwritten note from Colorado Parks and Wildlife’s “Piceance Predator Project” with 17 dates in May and June 2017 documenting a dozen boars and sows killed, with dogs treeing bears and some bears released. One entry noted dogs on June 26 treeing a lactating sow that was killed with “2 cubs in trees close by!”

In January 2020, a Denver District Court judge dismissed a lawsuit filed by WildEarth Guardians that argued Colorado Parks and Wildlife’s predator plans for the Piceance and Upper Arkansas River basins violated state laws prohibiting lethal trapping.

Those laws do allow for trapping and killing animals for “bona fide scientific research.” Judge Robert McGahey Jr., ruled that the two predator projects qualified for exemptions from lethal trapping because they were providing new and relevant knowledge suitable for publication.

In 2018, Colorado Parks and Wildlife removed an unreported number of mountain lions from the 3,000 square-mile Upper Arkansas River Basin and has been studying the impact of that reduction on mule deer populations.

This article was first published by The Colorado Sun on 5 April 2021. Lead Image: Colorado Parks and Wildlife planned to kill about half of the mountain lions in the Upper Arkansas River Basin between Leadville and Salida. (Provided by the National Park Service).

What you can do

Support ‘Fighting for Wildlife’ by donating as little as $1 – It only takes a minute. Thank you.




Fighting for Wildlife supports approved wildlife conservation organizations, which spend at least 80 percent of the money they raise on actual fieldwork, rather than administration and fundraising. When making a donation you can designate for which type of initiative it should be used – wildlife, oceans, forests or climate.


Dive in!

Discover hidden wildlife with our FREE newsletters

We promise we’ll never spam! Read our Privacy Policy for more info


Founder and Executive Editor

Share this post with your friends

Leave a Reply

Notify of

1 Comment