Everywhere you look on the McNeil elk feed ground west of Bondurant, you see the bones and hides of dead elk. Rancher Steve Robertson says many are left behind from wolf kills. He tells of seeing elk chased by wolves here just this last winter.

“The steams boiling off them, their tongues are hanging out,” he says. “And then two weeks later all those elk were killed on the feed ground. And the elk, they can’t go anywhere they’re snowed in, they’re trapped.”

Such a high surplus killing, as it’s called, with 19 elk killed and left uneaten in one night, has never been seen before on Wyoming's elk feed grounds. Then in another instance this winter, a second pack of wolves known as the Dell Creek Pack, also started killing large numbers of cattle. The U.S. Fish and Wildlife Service can’t act when wolves commit surplus kills on elk, their natural prey. But when they started chronically killing cattle, the agency decided to do what they promised when they introduced the species 20 years ago: they started killing off the wolf pack.

Today, Robertson is taking me on a horseback ride to get a view of his grazing allotment that borders the McNeil elk feed ground where the 19 elk were killed. In just a couple weeks, he'll be releasing thousands of head of cattle into this country. Riding up the ridge, we see lots of wolf tracks.

“We had a hard rain two days ago? Three days ago?” he says, climbing off his horse to get a closer look. “These tracks, they were made in that rainstorm.”

He says, he's never had problems with wolves in the past, but now with so many large packs moving in, his job has gotten harder.

“We put our cattle where they need to be and go back the next day and the wolves have chased them out of there. So that's a daily effort to try to comply with our permit,” he says. “Plus, if you're moving your cattle all the time, they don't grow.”

Robertson says he'd like to see the wolves taken off the Endangered Species List again, like they were from 2012 to 2014. He says, in those days, there weren't so many conflicts because hunting kept wolf numbers under control, and the Wyoming Game and Fish Department had more people managing them.

One was Large Carnivore Biologist Ken Mills. He says what's happening in Bondurant is rare. He shows me a moose jaw from a wolf kill with tooth decay so bad it ate a hole through the bone.

“You know, that's way beyond a root canal,” he says. “So you can imagine the pain that that one's dealing with.”

Pain that ended when a wolf took the moose down. Mills says wolves keep elk herds healthy by killing the diseased. He says it's unknown whether the 19 elk killed were sick, but hoof rot has spread and killed hundreds of elk on feed grounds recently.

But Mills says, whatever the reason for the surplus kill, there’s still too many wolves in the area.

“The goal of the Game and Fish is to manage wolf populations at a level that's low enough to sustain elk populations,” he says. “And we know what that level generally is six to seven wolves per 1000 elk.”

At Bondurant, there’s now 25 wolves for 1500 elk. U.S. Fish and Wildlife Service Wolf Coordinator Mike Jimenez says it’s not just Bondurant that’s seeing lots of wolves.

“It's the highest population in the history of the program,” Jimenez says. “There are over 380 wolves in over 48 packs in Wyoming.”

In the original agreement, though, the state only agreed to manage 100 wolves in ten packs. Jimenez says the wolves have run out of good mountain habitat and are moving down into ranching country, like Bondurant. He says that puts a heavy burden on ranchers.

“They try to avoid conflicts,” he says. “They have herders, they have riders, they have calving in fenced areas, they use guard dogs for sheep.”

But when the Dell Creek wolves still killed over ten cattle, Jimenez says, the Fish and Wildlife Service was forced to use aerial gunning, shooting them from a plane until they stopped preying on cattle.

“We removed nine of 16 animals,” he says. “The pack has since moved. They do have a den, they do have pups. And there's now probably around six or seven wolves. They've moved away from the livestock and that's worked really well.”

Wyoming Game and Fish Chief Game Warden Brian Nesvik says when the state managed wolves, this kind of thing rarely happened.

“During the time when we had authority, there were less wolves that were shot out of helicopters or airplanes.”

Nesvik says wolves also didn’t bother cattle as much around Bondurant. He says the public outcry over the killing of the Dell Creek wolves shows how divided people still are over wolves.

“I honestly believe that the best way to get folks to embrace wolf populations being on the landscape is through state management,” he says. “Federal management does not perpetuate a feeling of ownership in this species, it just doesn't.”

And state management does seem to be working in Montana and Idaho where wolves were delisted by Congress in 2011. Populations in those states are even higher than Wyoming’s, even with legal trophy hunting.

But Tim Preso, an attorney with Earthjustice, an environmental group that fought to get Wyoming's wolves relisted, says the difference between Wyoming and those other states is Wyoming’s management plan, “which has this widespread predator zone with unlimited killing,” he explains.

Preso says in Wyoming’s plan, wolves only get trophy animal status in the northwest corner of the state, which means stronger protections and limited hunting. In the other 85 percent of the state, they were classified as predators like coyotes and could be killed on sight.

“I mean, the United States didn't spend millions of dollars to recover wolves just so they could all be shot again.”

The debate over Wyoming’s approach to managing wolves is still tangled up in courts. Because of that, there doesn’t appear to be a clear path to delisting wolves anytime soon. In the meantime, the wolf populations in Wyoming continue to move south.

Riding back along the creek, Rancher Steve Robertson brings his horse up short and points. Three grey-white wolves flash in the red willows and then dart up a steep hill. They stop once to look back, and then they're gone. We sit on our horses watching a long time. Even though it means a greater threat to his cattle, Robertson says it’s still always fun to spot wolves.