Another gray wolf that was brought to Colorado as part of the state's reintroduction program has died, state and federal officials said on Monday afternoon.
In a press release, Colorado Parks and Wildlife (CPW) said they received a mortality alert for a male wolf in northwest Colorado on May 31.
The wolf had been brought to Colorado from Canada as part of the January 2025 reintroduction, CPW confirmed to the Scripps News Group in Denver. It is the fifth wolf from the original 15 released that month that has died.
As with any wolf death in Colorado, the U.S. Fish and Wildlife Service is investigating because gray wolves are a federally listed species under the Endangered Species Act. The USFWS will determine its cause of death. That investigation is ongoing.
No other details were available from either agency, however, CPW added that it is continuing to monitor four potential den sites.
"It is likely there are an unknown number of new pups that were born this year," CPW said. "CPW is developing plans for the coming year’s translocation efforts, so Colorado’s wolf population will continue to grow, leading toward a self-sustaining population."
Monday's announcement came just a few days after CPW said they had killed a year-old wolf from the Copper Creek Pack that had apparently been involved in a series of attacks on livestock in Pitkin County. That wolf, considered an adult, was one of the pups born in Grand County in the spring of 2024.
The Copper Creek Pack is the only confirmed pack in the state and was captured last year following multiple depredations. They were re-released in January.
Colorado's gray wolf reintroduction program began in December 2023, when CPW released 10 of the animals.
Fifteen wolves were brought to Colorado from Canada in January 2025 during the second round of reintroductions.
As of the time this article was published, four males and two females have died:
- March 16: A male wolf was killed by Wildlife Services in Wyoming after it was found at a property where multiple sheep had been killed earlier that day
- April 9: A male wolf died after traveling into Wyoming
- April 20: A female wolf died in Rocky Mountain National Park
- May 15: A female wolf died in northwest Colorado
- May 29: A male wolf, which was born in Grand County within the Copper Creek Pack, was killed by CPW after multiple depredations
- May 31: A male wolf died in northwest Colorado (this story)
In the past, CPW has stressed that wolf survival in Colorado is currently within normal margins and that mortalities were taken into account when building the 261-page Colorado Wolf Restoration and Management Plan.
Colorado's wolf reintroduction management plan lists the goal of translocating 10 to 15 wolves per year for a total of 30 to 50 wolves over three to five years.
After that point, the active reintroduction efforts will stop, and CPW will focus solely on monitoring to see if the population is self-sustaining.
The below list outlines a breakdown of the known wolf population in Colorado:
- 7 wolves surviving from the original 10 that were released in December 2023 (one died of a likely mountain lion attack, a second died from injuries sustained prior to his capture as part of the Copper Creek Pack relocation effort, and a third wolf became sickly and died)
- Four of the five wolf pups born in the spring of 2024 (one male was killed after multiple depredations in Pitkin County)
- 10 wolves surviving from the 15 that were released in January 2025 (one was shot and killed by Wildlife Services in Wyoming earlier this month, a second died of unknown causes in Wyoming, a third died in Rocky Mountain National Park, a fourth died in northwest Colorado and this story is about the fifth death)
- Two wolves that moved south from Wyoming several years ago
- One uncollared wolf that was last known to be in northwest Moffat County in mid-February. It is not clear if it is alive or still in the state.
- Possible, but unconfirmed, wolf in the Browns Park area
Below is the most recent map of the wolves' movements around Colorado.

Want to learn more about Colorado's wolf reintroduction? You can explore the timeline below.
This story was originally published by Stephanie Butzer with the Scripps News Group in Denver.