The North Park pack, which often crosses into Wyoming where hunting wolves is legal, gained notoriety last year after birthing Colorado’s first known litter of pups in 80 years.
Travis Duncan, spokesperson for Colorado Parks and Wildlife, said in an email that the agency cannot yet confirm whether the slain wolves were in the North Park pack but will continue to monitor the animals “if and when they are next seen in the area.”
Duncan added that at least two wolves were seen Friday in northern Colorado.
In Colorado, killing a wolf can bring a $100,000 fine and up to a year in prison. But once all four paws are across the border into Wyoming, wolves are in the state’s “predator zone” where anyone can legally hunt the animals without a license.
The Wyoming Game and Fish Department did not immediately respond to a request for comment.
The difference in state laws could impede Colorado’s planned reintroduction of wolves that was narrowly approved by voters in a controversial 2019 ballot initiative. The introduction is planned for 2023 on the sparsely populated Western Slope.
Earlier this year, authorities from Yellowstone National Park reported that 20 wolves had wandered out of the park and were killed by hunters. At least one pack—the Phantom Lake Pack—lost most or all of its members and is considered “eliminated.”
“It’s very clear that wolves need to be protected, perhaps permanently, from this sort of unregulated slaughter,” said Rob Edward, adviser to the Rocky Mountain Wolf Project, an organization fighting for reintroduction.
Edward said wolves help maintain a balanced ecosystem in part by culling their prey populations including elk, moose, and deer.
The reintroduction of wolves in Colorado remains hotly opposed by ranching organizations worried about losing livestock to the predators. Last year, Colorado Parks and Wildlife confirmed the state’s first livestock kill by wolves in decades. The agency reimburses ranchers for the losses.
The Colorado Cattleman’s Association did not immediately respond to a request for comment.