The relationships between grizzly bears and road densities were studied along the South Fork of the Flathead River. Thirty-nine grizzly bears were trapped, collared, and monitored from 1987 to 1992.

Areas with total road densities exceeding 2.0 miles of road per square mile were used by bears less than expected. Adult females used unroaded areas greater than expected. Areas with open road densities greater than 1.0 mi / mi2 were used by adult females and males less than expected.

Areas within 100 meters of a road were used by bears less than expected; areas greater than 500 meters from a road were used more than expected.

The "moving window" technique is recommended for calculating road densities. The entire analysis area has an average open road density of 0.63 mi / mi2 and meets current road density standards. The average total road density is 1.13 mi / mi2. Using the "moving window" technique, 26% of the analysis area exeeds the 1.0 mi / mi2 standard. Twenty-two percent of the core study area had a total road density greater than 2.0 mi / mi2.

It is concluded that if unroaded habitats are reduced in quantity or size, the number of adult females will eventuyally decline. To increase bear nmbers and survival, adequate secure habitat shoul be maintained at all elevations.