White Rim Trail

A hundred-mile loop on the white sandstone bench between the canyon rim and the Colorado and Green rivers. Street-legal bikes only (national park), and every vehicle needs a day-use permit from Recreation.gov even for a single-day ride; camping is at designated sites by advance backcountry permit only, book months out. Shafer switchbacks down, Murphy Hogback and Hardscrabble the two steep technical spots, deep sand near the Green River side. No water anywhere on the loop. Impassable when wet. Late March–May and September–October; summer is dangerous heat below the rim.