First Death Reported in Colorado's 2025 Wolf Reintroduction Cohort

Federal investigators are examining the death of a female gray wolf in northwest Colorado on January 16—the first reported mortality from Colorado's 2025 wolf reintroduction cohort and a potential test of the state's fledgling restoration program.

The death raises questions about survival rates in the young reintroduced population as the program enters its next phase.

Colorado Parks and Wildlife confirmed that wolf 2504, part of the 15 wolves translocated from the central interior of British Columbia in January 2025, died in northwest Colorado. Because wolves are federally protected under the Endangered Species Act, the U.S. Fish and Wildlife Service is investigating.

"A final determination of the cause of death will not be made until the investigation is completed, including the necropsy, a foundational component of the overall investigation process," CPW said in a January 20 media statement. No additional details are available at this time.

The 2025 British Columbia translocation built on an initial release of ten adult wolves in December 2023. From that first cohort, CPW Director Jeff Davis reported last December that "our efforts this past year have resulted in seven surviving adult wolves and five pups from the initial release of ten adult wolves in December, 2023"—a total of 12 survivors. The second cohort's survival remains under scrutiny.

Both groups have experienced losses. Two wolves from the 2023 cohort were illegally shot, and CPW reported in January 2025 that one wolf died during the capture process before release.

All translocated wolves wear satellite collars for tracking. CPW continues to monitor all known wolves in Colorado, including the four packs, and publishes monthly maps documenting pack movements and known mortalities.