The USGS Geographic Analysis and Monitoring program developed a national high resolution dataset that gives the distance to the nearest road every 30 meters (square) across the conterminous 48 states. These roadless areas are clustered mostly in the west around mountain ranges and deserts, with a few in the east ( the bayous of southern Louisiana, northern Minnesota, etc.).
The dark green signifies the areas farthest from roads and much of it overlaps with federally designated wilderness areas. Designated wilderness comprises only about 5% of the continental United States, and this map shows how special these areas are. (Click on the map to enlarge it.)
What are your favorite roadless areas?
View the complete publication (Fact Sheet, 2005, Watts, RD, RW Compton, JH McCammon, CL Rich, and SM Wright. Distance to the nearest road in the conterminous United States. Fort Collins, CO: USGS)