BIGGS, Ore. -- The state Department of Fish and Wildlife plans to capture about 30 bighorn sheep from what’s become known as the "I-84" herd.

Motorists traveling on the stretch of freeway between Arlington and Biggs in north-central Oregon have come to expect seeing bighorns loitering like out-of-luck hitchhikers. And that’s a problem, said Nick Myatt, a wildlife biologist in the agency’s Baker City office.

State officials would prefer that drivers on that 22-mile stretch watch the road instead of trying to figure out if a particular ram’s horns have a full curl.

"Some of the sheep have been seen right down on the freeway," he said. "It’s getting to be a safety concern."

Biologists will haul the trapped bighorns to other parts of Oregon, including 10 sheep that will be released in the Burnt River Canyon about 20 miles southeast of Baker City.

The trap-and-transplant operation is tentatively scheduled for the first week of December, the Baker City Herald reported.

The bighorns will help augment the Burnt River Canyon herd. For most of the past decade, the herd’s population has hovered around 70. But biologists counted just 47 in 2006.

"We probably missed some, but it does appear the population is declining," Myatt said.

ODFW first brought bighorns to the Burnt River Canyon in 1987, when biologists released 15 sheep. Those bighorns came from Leslie Gulch in Malheur County.

The Burnt River bighorns, like those that roam the I-84 corridor, are of the California subspecies. Baker County also harbors herds of Rocky Mountain bighorns, the other type of wild sheep that lives in Oregon.

Myatt says biologists speculate that cougars are somewhat responsible for the decline. But to get more exact information, the bighorns from the freeway herd will be fitted with a collar that emits a radio signal. Biologists can track those signals and monitor the bighorns’ movements.

"We’d like to have a better idea of the extent of their range," Myatt says.

The collars will also send a unique signal if they are stationary for a certain time, such as when a sheep dies. If biologists find the carcass quickly, they often can figure out what led to its demise.