Plans to reintroduce grizzly bears to the area as an experimental population have languished. The bear that was killed migrated to the area on its own and therefore carried special protections as a member of a threatened species.

Still, state and federal authorities are not pursuing criminal charges against the hunter, or his two guides, because of the prolonged absence of grizzlies in the region.

If the study finds other grizzlies have returned on their own, those bears would also be considered threatened, and the region could be recognized as containing a threatened species under the Endangered Species Act.

That designation would only apply, Nadeau said, if the study found an established population, loosely defined as two females with cubs over a period of five years.

"We don't have anywhere near that kind of information right now," he said. "It's possible we could get something along those lines through this work next summer."

Genetic testing on the bear that was killed found it's likely a descendent from a population roaming in northern Idaho's Selkirk Mountains.

Biologists say the bear migrated 140 miles south and crossed two major highways to explore the northern fringes of an ecosystem experts have been expecting bears to discover on their own for years.

"These young males will travel extensively between the ages of 3 to 6," said Nadeau. "It's high quality grizzly habitat, and it's along a good travel corridor."

Bringing grizzlies back to the Selway-Bitterroot has long been a priority for grizzly advocates because the landscape is considered a bridge to connecting grizzly populations in Yellowstone National Park with bears elsewhere in north Idaho, Montana and British Columbia.

But even if bears are in the area, Nadeau said, confirming their existence will be difficult.

"These animals are very good at hiding and living their lives unbeknownst to humans," he said.