Chronic wasting disease reaches Pinedale

An incurable neurological sickness that causes elk, deer and moose to wither away and eventually die has spread to the northern reaches of the Green River Basin.

The arrival of chronic wasting disease in Sublette County became official in mid-February, when Wyoming Game and Fish Department technicians whose job is to sweep the countryside for the malady sampled a dead mule deer doe at a home near the Pinedale Airport. A relative of mad cow disease, CWD has been found in Star Valley, near Dubois and within Green River city limits, but never before farther north in the river basin — meaning its leading edge jumped somewhat unexpectedly toward uninfected Jackson Hole.

“It was a leap across the landscape, without connectivity to other elk, deer and moose hunt areas that have tested positive,” Game and Fish Deputy Chief of Wildlife Scott Edberg said.

A “think tank” at Game and Fish, he said, plans to brainstorm theories about how the disease is showing up in places isolated from known areas with CWD. There was a similar occurrence about a year ago, when a CWD-positive mule deer was discovered dead outside Thayne.

“It could it be migration,” Edberg said. “Who knows?”

The mule deer stricken with CWD was discovered within hunt area 139, which is relatively close to elk feedgrounds at Soda Lake, Fall Creek and Bench Corral.

Wyoming’s chronic wasting disease management plan calls for officials to reassess feeding operations and consult with federal land and wildlife managers when the disease shows up in any species near a feedground. The concern is that dense concentrations of elk drawn to hay all winter will exacerbate spread of the disease.

CWD has so far not been found in elk in the feedground region — mule deer have been the conduit for the spread.

Edberg said Game and Fish has stepped up surveillance near feedgrounds, including hiring the technicians who sampled the positive Pinedale deer. Some 3,350 CWD samples were taken in 2016, more than doubling the effort from a few years ago, he said.

“Management-wise,” Edberg said, “we’re trying to start feeding later, stop earlier and keep feed spread out.”

Sublette County residents, he said, shouldn’t expect immediate wholesale changes to feedground or mule deer management because of CWD’s arrival.

One Pinedale hunting outfitter, Erick Kirchner, said he’s not overconcerned about the standalone diagnosis in his area, but worries for the future of the Green River basin’s deer and elk herds.

“We have one documented case here,” said Kirchner, who owns Ace-in-the-Hole Outfitters. “That’s certainly far from an epidemic, but it could become an epidemic. Everybody — game managers, hunters, conservationists — we’re all afraid of that.”

After it has appeared on a landscape, CWD is impossible to eliminate, because prions, the disease’s vector, can survive in soil and vegetation outside of animals. National Elk Refuge officials are bracing for the disease’s arrival and have said they believe the initial detection is inevitable and possible at any time.