Study conducted in Superior National Forest in Minnesota. The area consisted of a 975-km2 region of land where road density exceed the 0.58 km/km2 thought to be the maximum threshold for wolf survival, but was adjacent to an extensive area having fewer roads. 71 wolves were radio tagged between 1969 through 1986; 15 (24%) died of human causes, 17 (24%) probably were killed by humans, and 17 died of natural causes. The signals from 14 others were lost prematurely, which could have indicated radio failure, dispersal or additional human caused mortality. Total known or probable human-caused mortality was estimated at 69%. The author concluded that all though his study area contained 26% more roads than other areas of similar habitat where wolves did not survive, the fact that it lay adjacent to other regions with lower road densities allows wolves to survive in relatively small areas of high road density. He also concluded that road density thresholds described by other studies applies most directly to areas not adjacent to large reservoirs of occupied wolf range.