JACKSON, Wyo. (AP) — An operation to kill the mountain goats that have invaded Grand Teton National Park and threaten the existence of the park’s struggling bighorn sheep herd is beginning Sunday, officials said.

A large swath of the high Tetons, including the north and west slopes of the iconic Cathedral Group, will be closed to the public as aerial gunners contracted by the park spend up to a week locating and shooting at the approximately 100 goats, the Jackson Hole News & Guide reported.

“We’re trying to be efficient and effective — so doing this as fast as possible in the most efficient way — and we believe that the aerial operations does that,” park spokeswoman Denise Germann said.

Germann had no prediction about how many animals would be targeted, but said it’s possible that at least one more week of aerial shooting will occur, depending on how this operation goes.

“This will be our initial action, and we’ll see how it goes,” Germann said. “It’s a very unique situation for Grand Teton National Park.”

Park officials have also authorized ground-based hunters to kill goats, but that will not occur this winter, she said.

Flights to locate the goats begin Sunday and the shooting, contracted to Oregon-based Baker Aircraft, is set to begin Monday, depending on the weather. Shooters will use non-lead rounds from a shotgun or rifle, with the weapon type depending on the conditions.

The mountain goat population, migrants from the Snake River Range, has risen from estimated 10 to 15 animals seven years ago to recent estimates of more than a hundred. The habitat has the potential to support several hundred, officials said.

The bighorn sheep herd, by contrast, is considered fragile. They have been pushed out of some of their best habitat by backcountry skiing activity, and their existence is threatened by potential disease transmission by the mountain goats.

Park officials first proposed eradicating the Tetons’ goats in 2013, and plans were finalized late last year.

Eliminating wild goats from the Tetons has received broad public support. But the park’s draft plan released in 2018 was changed to allow for some goats to be relocated if suitable areas were identified.

Another change allowed meat from the killed goats to be salvaged, but recovering any animals shot this coming week is unlikely, Germann said.

“We will retrieve carcasses if we can safely do so, but we believe that may be very challenging,” she said. “If we do recover any carcasses this go-around, they will be used for research purposes.”

The research project, she said, is a collaborative effort with the California Department of Wildlife and University of Utah to look at body condition and nutrition in wild goat herds.

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