The first gray wolf to be released on Colorado soil darted out of the metal crate and dashed up a hill to nearby trees in Colorado’s central mountains, turning slightly as he ran to look back at the governor and other officials gathered Monday to watch the historic release.

The wolf and four others set free Monday on state land in Grand County were the culmination of three years of work to implement a first-of-its-kind reintroduction of the controversial predator to the state.

Colorado wildlife officials captured the wolves in Oregon on Sunday and flew them to Colorado for release, Colorado Parks and Wildlife announced Monday evening. Colorado Parks and Wildlife officials said they would not disclose the exact location of the release in the north-central mountains to keep the canines and the agency’s staff members safe.

Colorado’s wolf reintroduction is the first voter-mandated reintroduction of the endangered species in the United States, where the apex predators once roamed from the Canadian border to the southwest.

Wildlife advocates have hailed the reintroduction as a much-needed chance to restore a crucial species to an ecosystem where wolves have not existed in large numbers since the early 1900s. But some ranchers and hunters have protested the effort, citing concerns about harms to cattle, sheep and hunting game herds.

“Today, history was made in Colorado,” Gov. Jared Polis said in a news release. “For the first time since the 1940s, the howl of wolves will officially return to western Colorado.”

The captured wolves were two juvenile females, two juvenile males and one adult male, the announcement said.

The five wolves came from three packs in Oregon. The wolves are expected immediately to disperse from the release site by up to 70 miles and stay on the move for weeks until they find suitable habitat.

Joanna Lambert, a professor of wildlife ecology and conservation biology at the University of Colorado Boulder who attended the release, lost her breath when she saw the wolves run on the forested mountainside deep in the Rocky Mountains.

“This is a moment of rewilding,” she said. “Of doing something to stave off the biodiversity extinction crisis we are living in … to make a difference in this era of extinction. And moreover, this is a source of hope not only for all of us standing here but for our younger generations as well.”

Colorado wildlife officials worked from dawn to dusk Sunday to capture the five wolves, said Eric Odell, CPW’s species conservation program manager, during a news conference Monday night. Two teams in Oregon used low-flying, fixed-wing planes to look for wolf tracks and analyze data from the wolves’ collars.

Once located, teams in helicopters shot the wolves with tranquilizers.

The helicopters then transported the wolves to a processing area where veterinarians and biologists checked their health, took blood and tissue samples, and fitted them with radio collars. Video from CPW shows the tranquilized wolves — their eyes covered with blindfolds and tongues lolling out of their mouths — laid out on tarps while staff members took measurements and checked their teeth. Then they were loaded into crates.

The wolves were flown to Colorado early Monday morning, Odell said. Wildlife officials considered the availability of prey as well as proximity to airports and ease of access when it chose five potential release sites on state land in Grand, Summit and Eagle counties.

“It’s a pretty majestic thing, a pretty awesome thing to see,” he said of watching the wolves run over the hillside after their release.

State wildlife officials will keep an eye on the released wolves’ locations, though the collars do not transmit real-time data. Once the wolves establish an area where they will live, the agency will work with people living nearby to minimize conflict, state officials said.

“My hope and my philosophy is really that we will learn to live with wolves and not against wolves,” said Dan Gibbs, executive director of the Colorado Department of Natural Resources.

The release relieved pressure on the agency to bring wolves to the state by Dec. 31 — the deadline set out in the ballot measure approved by voters. Colorado’s reintroduction is the result of a successful ballot measure that in 2020 put the question of whether to bring wolves back to voters.

The measure narrowly passed, 51% to 49%, fueled primarily by voters along the state’s urban Front Range.

“Living alongside wolves and other wildlife is part of life in the West, and we have the tools we need to successfully restore this piece of our natural heritage,” said Kaitie Schneider of Defenders of Wildlife, one of the groups that worked on the ballot initiative. “Now, we must allow these wolves to lead us toward the first self-sustaining wolf population Colorado has seen in over 80 years.”

Federal officials in the 1990s brought back wolves on federal lands in Wyoming and Idaho, where the creatures have since established successful packs despite years of litigation over their management.

Colorado, however, is the first state to reintroduce the species.

Wolves have roamed Colorado recently. They naturally migrated into northern Colorado from Wyoming in 2020 and established a pack of eight, though state wildlife officials believe only two of them remain in the area.

The wolves released Monday are the first of up to 50 expected to be released over the next three to five years. Colorado Parks and Wildlife plans to release up to 10 wolves from Oregon between December and March before restarting releases the following winter.

The agency continues to talk with other states about sourcing more wolves, CPW Director Jeff Davis said during Monday’s news conference.

Two ranchers’ groups sued state and federal wildlife officials days before efforts to capture the wolves in Oregon began, but a federal judge on Friday denied the groups’ request to delay the reintroduction.

The ranchers’ lawsuit and another lawsuit against the reintroduction, filed Dec. 14, are proceeding in federal court.

Davis declined to comment on the pending litigation Monday. The agency will continue to work with and listen to ranchers on the Western Slope and will perform its due diligence to minimize conflict with wolves and compensate ranchers for losses, he said.

“We don’t want rural landowners to feel like they’re in this on their own,” he said.

The Associated Press contributed to this story.

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