Rattlesnake Canyon in west-central Colorado lies within the Black Ridge Canyons Wilderness in the McInnis Canyons National Conservation Area and is renowned for its nine natural sandstone arches, the second-highest concentration in the United States after Arches National Park. Reached by a strenuous hike or seasonal high-clearance roads, the canyon’s main loop passes several major formations, including Cedar Tree Arch, also called Rainbow Arch, East Rim Arch, and Bridge Arch. Their prominent spans and openings, together with the canyon’s remote setting, make this one of Colorado’s most distinctive backcountry arch landscapes and a place valued for both geology and wilderness.