This is said to be the only guidebook that covers 4WD trails in western Montana. Back Roads Publications' "4x4 Trails in Western Montana," by Willie and Jeanne Worthy, a 226-page spiral-bound book, details more than 40 trails as well as side trips. There are turn-by-turn directions, mileage and GPS coordinates, histories of the early settlements, old mining areas, high-altitude lakes, and information on the area's geology and plant life. Routes range from easy outings to challenging roads. Price: $25 plus shipping