A gray wolf has died in Rocky Mountain National Park, Colorado Parks and Wildlife (CPW) said Thursday afternoon, marking the third wolf translocated from Canada to Colorado to die since their release in January.
CPW said the female wolf's collar sent a mortality alert to biologists on April 20.
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.
CPW did not have any additional information to share regarding this death.
Fifteen wolves were brought to Colorado from Canada in January 2025 during the second round of reintroductions. As of publishing time, two males and one female have died.
CPW stressed that wolf survival in Colorado is currently within normal margins and that mortalities were taken into account when building the Colorado Wolf Restoration and Management Plan. Brenna Cassidy, wolf monitoring and data coordinator with CPW, told Denver7 in December that wild wolves typically only live three or four years. Her PhD is centered on wolf mortality.
"It doesn't seem like very long, especially when you consider having dogs in our homes that live to be, you know, 12, 14, 16 years old," she told us at the time.
Colorado's 261-page 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.
In the short-term, the reintroduction will be considered successful if the survival rate is high, the wolves stay in Colorado, packs are formed and breed, and if wolves born in Colorado survive and go on to reproduce, according to the plan. Within the first six months of release, CPW hopes to have a survival rate of 70% or more. Anything less than that would "initiate protocol review," the plan reads.
With 12 of the 15 wolves from Canada surviving, that survival rate is currently at 80%.
Read the full wolf restoration and management plan below or here.
As of Thursday afternoon, the number of known wolves in Colorado is as follows:
- 7 wolves surviving from the original 10 that were released in December 2023
- Five wolf pups born in the spring of 2024
- 12 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 and this report is about the third death)
- Two wolves that moved south from Wyoming several years ago (both collared)
- One uncollared wolf that was last known to be in northwest Moffat County in mid-February
- Possible, but unconfirmed, wolf in the Browns Park area
Want to learn more about Colorado's wolf reintroduction? You can explore the timeline below, which outlines all of Denver7's coverage since the very beginning. The timeline starts with our most recent story.