Fascinating natural history, crystal stars, and stunning mountains all meet at this culturally and naturally diverse Arizona park. Sporadic rain-fall and extreme temperatures shape the unusual lifeforms of the Sonoran Desert. Organ Pipe Cactus National Monument preserves a portion of this desert ecosystem in a rugged wilderness of volcanic mountains and canyons, cactus-clad bajadas, mesquite-lined arroyos, and vast creosote plains.