A three-year study in the Cabinet-Yaak Ecosystem counted 42 to 55 grizzly bears using a hair collection and DNA analysis method similar to a 2004 study in Glacier National Park and the Bob Marshall Wilderness complex.

Grizzly bears were listed as threatened under the Endangered Species Act in 1975. The Cabinet-Yaak Ecosystem in northwest Montana and northeast Idaho is one of six recovery zones defined in a grizzly bear recovery plan. The U.S. Fish and Wildlife Service has established 100 bears as its benchmark for full recovery in the Cabinet-Yaak Ecosystem.

Kate Kendall, with the U.S. Geological Survey’s Northern Rocky Mountain Science Center, who led the 2004 study, spoke to the Lincoln County Commissioners about the results on Dec. 9. She presented her findings to the Interagency Grizzly Bear Committee later in Missoula.

The Cabinet-Yaak study began in 2011. The study area included 2.4 million acres in the Cabinet-Yaak Ecosystem, of which 1.7 million are in a federal designated Grizzly Bear Recovery Zone.

Crews eventually established 1,386 rub sites and set up 100-foot barbed-wire corrals baited with a scented lure across 395 cells in 5-by-5 kilometer grids. Grizzlies were detected in 26 percent of the cells and black bears in 98 percent.

A total of 18,761 hair samples were recognized, of which about 60 percent were sent for analysis, Kendall said. Collectively from the corrals and rub sites, scientists detected 38 individual grizzlies, of which 21 were males.

Additional grizzlies were detected or known from other methods, such as two full-time collared bears, Kendall said. Of the estimated 45 grizzlies total, 23 were males and 22 were females.

The 2004 study covered 7.8 million acres in the Northern Continental Divide Ecosystem, including Glacier National Park, Bob Marshall Wilderness Complex and surrounding areas. That “snapshot” population estimate came up with 752 grizzly bears.