Sespe Wilderness provides ample evidence of past violent geological upthrusts. The landscape is bleak and jagged, and if you climb high enough, you'll find pine trees growing at odd angles on boulder-swept hillsides. Sandstone cliffs rise as much as 500 feet above the water in places, and fabulous sandstone formations stand in portions of the area. You may see petroglyphs and other evidence of ancient Indians. The area is a part of the fourth largest roadless region left in the Lower 48, and it's the one closest to a large metropolitan area.
Numerous trails provide access, and human use is heavy.