In a rather unusual study, a group of indigenous people has mapped out a "grizzly highway" that stretches hundreds of miles through British Colombia, shedding light on bear populations in the area.

Conducted over three years, authors of the study identified nearly 60 individual bears, the majority of which travelled roughly 380 square miles - much farther than previously thought - in search of autumn-spawning salmon in the Koeye River.

The research was guided by the Heiltsuk First Nation, native Canadians who settled in the Koeye watershed more than 9,000 years ago and are reaffirming their guardianship of the area. Their findings were published recently in the journal Ecology and Society.

In order to minimize the impact of the study, the researchers used non-invasive DNA analysis methods to assess bear population numbers during salmon-spawning season. Instead of offering bait to the bears, they used scented wire snares that snagged small tufts of hair when grizzlies walked by, attracted by the smell.

From that bear fuzz scientists could then extract their DNA, thereby showing which bears used specific areas of the watershed.

The study also provides potential evidence of a declining bear population in the area driven by the decreasing availability of salmon.

"This study shows that protected areas are not enough. We knew that bears are wide-ranging, but this study shows how vulnerable they are to a variety of threats," Richard Jeo, a study author and scientist at The Nature Conservancy, said in a press release.

The Koeye River Conservancy is one of numerous protected areas designated by the Heiltsuk First Nation in the Great Bear Rainforest of British Columbia in 2009. This indigenous group sees it as their job to protect possibly threatened bears in their territory.

"We want to practice land and resource management with strong information empowering our decision makers," said study author William Housty, a member of the Qqs Projects Society, a Heiltsuk conservation group. "Whether it's regulating activities like forestry and tourism or indigenous-led advocacy to end trophy hunting for bears, ensuring that we ourselves are leading the best available science is a critical part of asserting our sovereignty and stewardship responsibility."