Who’s afraid of the big bad wolf? Apparently, a lot of Coloradans. A proposed 2020 ballot initiative would require Colorado Parks and Wildlife to reintroduce gray wolves to the state, and while the deciding vote is likely a year away, the measure is already driving a wedge in the Centennial State electorate. Advocates like the Sierra Club claim the animals, who disappeared from the state in the 1940s due to extermination efforts, would strengthen our ecosystem: As apex predators, wolves kill off weak mammals and control the populations of midlevel carnivores like coyotes. Opponents, including the Rocky Mountain Elk Foundation, say there’s no need for a restoration program because the canines could easily move here from neighboring states without human intervention. Ranchers, meanwhile, worry an influx of gray wolves could threaten their livestock. To help you understand what the actual impact might be, we examined four other times Colorado brought about the return of long-lost animals.

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Cats, Out Of The Bag
The restoration of lynx provides a valuable lesson for carnivore recovery. In 1999, more than 25 years after the felines vanished from the state due to factors such as increased development, Colorado Parks and Wildlife (CPW) released 218 lynx that had been captured in Alaska and Canada into the San Juan Mountains. Many of them died of starvation—the result, CPW says, of a now-discontinued practice of freeing imported animals without a controlled period of acclimatization. The strong survived, however, and a 2010 survey found that a third generation of Colorado lynx was stable and thriving. Current estimates suggest there are 150 to 250 roaming the southwestern corner of the state.

Photo courtesy of Tom Reichner/Alamy Stock Photo

OG Elk
The Instagram-ready herds of majestic elk in Rocky Mountain National Park have a secret­—they’re from Yellowstone National Park. In the early 1900s, after hunters nearly wiped out the species in the state, titans of Colorado industry (including F.O. Stanley of Stanley Steamer motorcar fame) imported more than a dozen elk from Yellowstone. Legend has it Stanley acclimatized the critters in a controlled environment near his namesake hotel in Estes Park before releasing them into the wild. Colorado is now home to some 287,000 elk, more than any other state. Of note: The elk population first skyrocketed in the 1940s, right around the time gray wolves disappeared.

Photo courtesy of Jennifer Barfield

Baby Boom
It’s well-known that hunters killed off most of the millions of bison that once roamed the West. Fewer people understand that a major reason the creature’s numbers have been so difficult to restore is brucellosis, a disease that causes pregnancy complications for the animal. In 2015, though, Colorado State University researchers moved 10 genetically pure, brucellosis-free bison from Yellowstone to the plains of Fort Collins. Under the scientists’ purview, the herd’s population has swelled to more than 70. This past June, the animals began traveling forth to multiply: Two members of the Laramie Foothills clan were sent to the Oakland Zoo to launch a similar conservation effort.

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Turkey Takeover
Current estimates suggest Colorado has more wild turkeys than at any other point in its history. But in the 1980s, the fowl was rare enough that CPW instituted a concerted reintroduction effort, which included bringing in birds from neighboring states like Oklahoma, Kansas, and Texas as well as collaborating with local sporting groups to limit hunting. The program was so effective that today, around 35,000 birds can be found across 53 of the state’s 64 counties. Some of them have even made frequent appearances in not-so-natural habitats, including in 2012 when a small flock roamed the Denver Tech Center for a few weeks.