| Mattson, Knight | D.J., R.R. | Effects of access on human-caused mortality of Yellowstone grizzly bears. | 1991 | Report by the Interagency Grizzly Bear Study Team, Bozeman, Montana |
The study analyzed bear locations and mortalities in the Greater Yellowstone Ecosystem.
The study found that increased access facilities increased bear-human encounters, which usually has negative consequences for bears.
Areas impacted by secondary roads have roughly 5X the mortality rate of the Yellowstone Park backcountry. Areas impacted by major human developments have roughly 11X the mortality rate of the Yellowstone Park backcountry.