Environmental groups, meanwhile, are pushing for the release of more captive-bred wolves to bolster the population in those states.

In Colorado and Utah, opponents argue that wolves would inflict costly and cruel losses on cattle and sheep and decimate big game herds that support the lucrative hunting industry. They also say Mexican wolves aren’t native to their states, and bringing them in could taint the gene pool if they bred with gray wolves roaming down from the northern Rockies.

“We don’t need to introduce another large predatory carnivore to the state,” Colorado Wool Growers Association director Bonnie Brown told the Colorado Parks and Wildlife Commission last week. Mountain lions are already killing pets in urban areas bordering open country.

Wolf advocates say the fears are overblown, and that Mexican wolves need more ranges to avoid extinction. Parts of Colorado and Utah would be ideal for wolves, said Jonathan Proctor of Defenders of Wildlife, and he argued that both states are within the wolves’ historical range.

The West needs wolves to help restore balance to the environment, he said.

“It’s we humans who have eradicated all the wolves from the West,” Proctor said. “It’s our responsibility to bring this animal back.”