Cottonwood Wash Road — San Rafael Reef to Sinbad Country via Temple Mountain

Temple Mountain sits at the heart of one of the most underrated overlanding zones in Utah — the inner Sinbad country of the San Rafael Swell. The Cottonwood Wash Road enters the reef via a crack in the sandstone that barely looks passable, then drops into the wash itself where the track alternates between firm sand and axle-deep loose stuff depending on recent weather. Old uranium mine tailings mark the mid-route waypoints at Temple Mountain, where Cold War-era prospecting camps still haunt the benches above the wash. Beyond Temple Mountain the canyon opens into the Sinbad basin, a broad isolated interior valley ringed by the Swell’s signature tilted reef fins — one of the more dramatic natural theaters in the Colorado Plateau and rarely visited even by Utah standards.

Moderate difficulty overall, but the wash sections after any rain will swallow a two-wheel-drive vehicle permanently — treat it as a high-clearance job year-round. The sand can also be deceptively soft in the lower canyon; airing down to 18–20 psi helps considerably. Closest fuel and water are in Green River, roughly 25 miles north. No permit required; BLM-managed. Dispersed camping throughout Sinbad is wide open and genuinely remote — you may run two days here without seeing another vehicle. Best seasons are spring and fall; flash flood risk in summer thunderstorm season is real and not worth testing.