Jun. 14—Errant cattle roaming the Valles Caldera National Preserve have spurred a lawsuit from three conservation groups that contend federal land and wildlife managers have failed to prevent the rogue cows from invading the park and encroaching on endangered species.

The groups argue the U.S. Forest Service and U.S Fish and Wildlife Service have allowed the cows’ intrusion for years without taking the necessary steps to resolve the problem, allowing the cattle to degrade riparian areas and grasslands vital for three endangered species.

By not actively seeking remedies, the agencies have violated the Endangered Species Act and have shirked their duties as government overseers of public lands and wildlife, the 45-page complaint says.

The complaint levels most of its criticism at the Forest Service, which is in charge of the permitted grazing areas, known as allotments, in the Santa Fe National Forest bordering the 89,000-acre preserve.

Cattle, sometimes in the hundreds, have slipped through damaged or downed fences and assembled in the caldera to feed on meadows much lusher than the allotments where the grass often has worn thin over the years. There are limited areas within the preserve where cattle can graze, but almost all of it is protected and off-limits.

“The Forest Service has violated its duty to ensure that its actions do not jeopardize the continuing existence of the endangered Jemez Mountains salamander, threatened Mexican spotted owl, and endangered New Mexico meadow jumping mouse,” the complaint says. “The Forest Service is obligated to ensure that any action it undertakes or authorizes will not jeopardize the survival and recovery of endangered and threatened species.”

Representatives of the two agencies said their long-standing policy is to not comment on active litigation.

The groups that filed the suit are Western Watersheds Project, Caldera Action and WildEarth Guardians.

Two years ago, they threatened to sue these two federal agencies and the National Park Service but decided to forgo the legal action when the agencies laid out plans to tackle the problem.

Now they’re following through with the litigation but are leaving out the Park Service because of what they say is the agency’s good faith effort to remove the stray cows from the preserve.

The Park Service is hiring wranglers to ride on horseback and corral rogue cattle. If the ranchers who own the cattle can be identified by tags, branding or other marks on the animals, they are contacted and told to retrieve their cows.

“That’s a great step,” said Cyndi Tuell, Western Watersheds’ Arizona and New Mexico director. “They have to have a way to get those cows out of the preserve as soon as possible. We appreciate them doing that.”

Last year, when an estimated 850 cows trespassed into the preserve, the Park Service notified the owners and ordered them to get the cows, Tuell said. The agency also tracked how much vegetation was foraged, she said, adding it’s important to know the wayward cows’ impacts.

For more than 100 years, the caldera was part of a working cattle ranch. The federal government bought the property, known as the Baca Ranch, in 2000 in a $101 million deal.

The preserve later gained additional protections that barred cattle grazing in most areas, and its jurisdiction was handed over to the Park Service in 2015.

Cows have invaded the caldera since at least 2017, finding openings in fences damaged by wildfire, falling trees and vandalism. Tuell and other public land advocates suspect some ranchers are cutting the fence so their cattle can escape and munch on the preserve’s more plentiful grass, but that never has been proved.

The Forest Service has resisted taking any new approaches to rein in the cattle, Tuell said. For instance, she noted, the agency has $1 million to repair and build fencing but rejected the suggestion to install sturdier metal-pipe fences instead of barbed wire, claiming it’s too expensive.

The Forest Service also continues to let cattle graze in areas where the fencing is damaged rather than limit them to tracts where the fences are intact, such as areas north of the caldera, Tuell said.

“It’s a problem with a solution that the Forest Service has chosen not to take advantage of,” she said.

Tom Ribe, Caldera Action’s executive director, said the Park Service should exercise its authority to fine ranchers who let their cattle trespass in the preserve. Right now, no such deterrent exists, Ribe added.

“The National Park Service needs to make it more expensive,” he said.

Ultimately, it’s the Forest Service’s responsibility to manage the allotments — which includes making them secure — to keep the cattle away from the preserve, Ribe said.

The larger issue is the agency allowing those parcels to be overgrazed, he said.

The complaint notes that when the allotments become depleted, cattle naturally seek more verdant fields where they can feed — in this case, the caldera, where faulty fencing enables their encroachment. It contends the Forest Service should reduce the amount of cattle on allotments to give the grass there a chance to thicken.

Cattle grazing in riparian stretches often denudes stream banks, warming the water and knocking sediment into the streams, both of which can hurt fish, Tuell said. The cows also defecate in the water, sending E. coli downstream to where people are fishing and wading, she added.

Cows congregating along streams damage the jumping mouse’s riparian habitat and eat the grass on which the mouse relies, the complaint says..

Their impacts on the Mexican spotted owl are indirect, thinning the grass cover for the prey the birds hunt and subsist on, it says.

Both Ribe and Tuell said suing the federal government was a last resort they could no longer avoid.

When the groups threatened litigation two years ago, the agencies became more serious about addressing the problem, Ribe said.

“A little bit of extra prodding seems to have been helpful,” he said.