I did a review of my topo map of the Bob Marshall Wilderness (inc Scapegoat & Spotted Bear Wildernesses). The distance of 38 miles straight line to the nearest road is just not possible in the Bob. Maybe they mean the nearest paved road, maybe they are talking trail distance, but not straight-line distance to nearest forest service road.
In order to reach the 38 mile distance, the wilderness & ajacent roadless areas would need to be 76 miles across. It is simply not that big on an East/West axis.
The farthest I could find was about 13 miles, but I would need to use a drafting table and two compasses to get an exact measurement.