Update: On Dec. 11, 2025, Colorado Parks and Wildlife officials captured and returned a wolf into Grand County, Colorado, that had traveled into New Mexico.
Since their reintroduction to the state in late 2023, Colorado wolves have roamed widely. In October, a wolf activity map issued by Colorado Parks and Wildlife showed that wolves are nearing the state’s southern and western borders.
Highlighting the watersheds where biologists located at least one collared wolf during the previous month — without revealing specific location data — the map showed that wolves have been present in Archuleta, Conejos, and Costilla counties, all of which border New Mexico. Wolves can cover up to 30 miles in a single day, and one collared wolf has traveled about 400 miles since she was reintroduced in January.
State lines don’t mean much to canids, but they are an issue for wildlife managers. After Colorado voters approved a ballot measure in November 2020 that directed the state to reintroduce wolves, state wildlife officials from Arizona and New Mexico raised concerns about Colorado’s reintroduced wolves moving into their states — and messing with the recovery of Mexican gray wolves, the rarest subspecies of gray wolf in North America.
In 2023, wildlife managers from Colorado, Utah, Arizona, New Mexico and the U.S. Fish and Wildlife Service signed a memorandum of understanding with the express intent of keeping the Mexican wolf separate from other gray wolves. Signatories agreed to notify each other if wolves strayed outside their subspecies’ designated population areas — Colorado for gray wolves, south-central Arizona and New Mexico for Mexican wolves — and to capture and return them to their former stomping grounds. The result is a theoretical wolf-free zone across northern Arizona and New Mexico.
The latest map of Colorado wolf movement, released in November, doesn’t show as much southern activity as October’s. But wolves are almost certain to keep moving toward state borders — especially as maturing pups set off in search of their own mates and territory.
THE FATE OF WOLVES, more so than that of many other animals, depends on artificial lines. Yellowstone wolves that step outside park boundaries can be hunted, as can Colorado wolves that stray north into Wyoming.
Eric Odell, the wolf conservation program manager at Colorado Parks and Wildlife, said he’s not aware of another multi-state agreement requiring the return of wandering wolves. “It is very unique,” Odell said.
Credit: Colorado Parks and Wildlife
That uniqueness stems from Mexican gray wolves’ special status.
Mexican gray wolves, which nearly went extinct in the 1970s, were reintroduced to the Southwest in 1998 and are currently only allowed to exist in an experimental population area that spans south-central Arizona and New Mexico. Governors of Colorado, Arizona, New Mexico and Utah have long opposed Mexican wolves living north of Interstate 40, a major east-west highway, though that hasn’t kept some wolves from trying.
A Mexican gray wolf known as Taylor was found between I-40 and the Colorado state line this fall, outside the experimental population area. A few weeks after being captured and taken south, he was back on the north side of I-40.
As Colorado wolves move south and the occasional Mexican gray wolf slips north, a debate among wildlife managers, scientists, and environmental groups has reopened: Would interbreeding of the subspecies be good or bad for Mexican gray wolves?
Odell predicted that gray wolves would “swamp” the genetics of the smaller Mexican subspecies, eventually erasing the distinction between Mexican and other gray wolves. “It’s definitely a concern,” Odell said. “It was something we want to protect against happening.”
“Evolutionarily, ecologically, species didn’t have boundaries.”
Others argue that the arrival of wolves from the north would help save Mexican wolves by diversifying their gene pool; Mexican gray wolves struggle with low genetic diversity and show signs of inbreeding, like fused toes. “The bottom line is, we think it would be a good thing,” said Bryan Bird, southwest director of Defenders of Wildlife.
Doug Smith, a wildlife biologist and former leader of the Yellowstone Wolf Project, said the “age- old solution” for low genetic diversity is the arrival of wolves from other areas. “Evolutionarily, ecologically, species didn’t have boundaries,” he said. “That’s just an irrefutable fact. You can’t put a line on the exchange of genes. That’s been unbounded for millions of years.”
Despite the multi-state agreement, interactions could occur under the radar. Colorado’s adult wolves are collared, but their current pups are not. As the state’s wolf population grows, biologists plan to collar two wolves in every pack, which Odell called an “imperfect” way to keep track of their movements. To his knowledge, Colorado’s wolves haven’t slipped into neighboring states — yet. Bird predicted that it was only a matter of time: “These wolves will mingle at some point. It’s inevitable.”
IN THE MEANTIME, Colorado’s wolf reintroduction faces more pressing challenges. Of the 25 wolves reintroduced so far, 10 are dead — killed by mountain lions, poachers, and, after repeatedly killing livestock, the state’s own wildlife managers. The most recent death, in late October, is under investigation.
But more wolves are on the way — or, at least, they’re supposed to be. The third and final release of wolves in Colorado is scheduled to happen this winter. Colorado and British Columbia had signed an agreement to relocate 10 to 15 wolves in the coming months.
On Oct. 10, U.S. Fish and Wildlife Service director Brian Nesvik sent a letter to Jeff Davis, then-director of Colorado Parks and Wildlife, stating that wolves must be obtained not from Canada but from northern Rocky Mountain states — states that have turned down Colorado’s requests in the past. Nesvik alleged that importing wolves from Canada would violate federal guidelines for experimental populations of listed species.
“It’s frustrating to the effort of trying to restore wolves,” said Odell, adding that efforts to find another suitable source population are ongoing. Yellowstone’s Smith said that more wolves will give the state of Colorado more flexibility to manage problematic individuals. “To stop them midway through recovery hurts more than it helps,” Smith said.
Still, Odell argued that Colorado’s recovery effort has been successful to date, with 20 collared wolves and at least 10 pups on the ground as of December, and has followed all appropriate rules and regulations. “I think it gets characterized as a failure in a lot of ways, but it’s not,” Odell said. Still, the recovery effort is in a “tenuous position right now,” he said. “If we don’t get another batch of reintroductions this year, is it a failure?” Odell said. “I hope not.”
This story is part of High Country News’ Conservation Beyond Boundaries project, which is supported by the BAND Foundation.
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