LANDER - State and now tribal game managers have detected three new cases of chronic wasting disease, a fatal brain disease that can affect all members of Wyoming's deer family.

The new locations are in the Owl Creek drainage, north and west of Thermopolis. The disease had not previously been detected in this area.

"We're always concerned when we have a geographic expansion of this disease," said Terry Cleveland, director of the Wyoming Game and Fish Department.

Conservation groups immediately worried about the fact that chronic wasting disease is moving ever closer to northwest Wyoming and the elk feeding grounds south of Yellowstone National Park. Wyoming has 22 elk feedgrounds, plus the National Elk Refuge outside Jackson.

"It's clear that CWD is moving west across Wyoming, right towards the elk feedgrounds," said Lloyd Dorsey, the Greater Yellowstone Coalition representative in Jackson. "We've known for years that CWD is expanding its range, and unfortunately for our elk populations little has been done to alleviate the extreme wintertime densities of elk on feedgrounds which are perfect conditions for this disease and others to erupt. The time to phase out elk feedgrounds is now, before CWD hits."

On Friday, the Wyoming Game and Fish Department announced that two mule deer bucks, taken just north by northwest of Thermopolis in the lower Owl Creek drainage, had tested positive for the disease. On Wednesday, the Shoshone and Arapaho Fish and Game Department announced that a whitetail buck, taken one mile east of the Arapaho Ranch headquarters, had also tested positive. Ranch headquarters are in the upper Owl Creek drainage, in the northeast quadrant of the Wind River Indian Reservation.

The case on the reservation, about 20 miles due west of Thermopolis, is the most western case in the state. The most northern case was reported two years ago, south of Worland.

Larry Makeshine, director of the tribal department, said the whitetail buck appeared to be healthy when it was shot and killed by a tribal hunter. The lymph nodes of the deer were among a batch of 30 tissue samples sent for testing at the Wyoming Game and Fish Department's laboratory in Laramie.

Game and Fish Deputy Director Gregg Arthur directed Game and Fish personnel in the Cody region to remove up to 50 deer within a five-mile radius of where the two Thermopolis-area deer were killed.

He said that surveillance in other states has shown that it may be possible to slow down the spread of the disease if new cases are identified early.

Game and Fish Director Cleveland said 15 more deer in the area had been shot and tested since Oct. 27. "We haven't had any more cases in that hunt area."

According to Arthur, the additional sampling serves three purposes.

* First, it allows Game and Fish to determine the prevalence of chronic wasting disease in an area.

* Second, it may eliminate the disease in an area and prevent its spread to other areas.

* Third, it may allow Game and Fish to locate an area of infection that it can manage aggressively.

"Should more positives turn up, we will expand our efforts," Arthur said.

Makeshine said no decision has been made as of yet on how the tribes will respond to the case on the reservation. Cleveland said that whatever the tribes decide, Wyoming Game and Fish will fully cooperate.

Conservationists said the new cases show the agency should move quickly to protect elk in feedground areas.

"When this kind of threat occurs, specific proposals like closing elk feeding grounds, reducing competition between wildlife and cattle grazing on public land and checking all slaughter cattle for signs of mad cow disease should be seriously heeded," said Meredith Taylor of the Wyoming Outdoor Council. "This is a wildlife time-bomb waiting to go off."

Chronic wasting disease is a fatal neurological disease that has been diagnosed in wild deer and elk in 10 states and two Canadian provinces. Animals show no apparent signs of illness throughout much of disease course. In terminal stages, animals typically are emaciated and display abnormal behavior.

Tom Roffe, an infectious disease expert for the U.S. Fish and Wildlife Service, said the death toll among elk, after chronic wasting hits the feeding grounds, would be far greater than starvation losses from simply closing elk feedgrounds.

The closest comparison would be what has happened on commercial game farms, which have sustained 50 to 70 percent mortality when the disease hits, he said.

"But you can't say what will happen on a feedground, based on game farm experience, because as soon as they noticed chronic wasting disease, they depopulated the game farms," Roffe said.

Dave Gowdy, executive director of Wyoming Wildlife Federation, said closing the feedgrounds is highly controversial. But eventually, he said, Wyoming must acquire enough conservation easements or properties surrounding the feedgrounds to allow them to be closed and the elk both dispersed and well fed through harsh winters. The big question, he said, is whether Wyoming can achieve that goal before the disease hits the feedgrounds.