Geology in the Reserve
Perhaps the single most important factor in the creation of the landscapes and habitats of Washington County (and the reserve) is the Hurricane Fault. The fault bisects the county, and is visible as the Hurricane Cliffs which run south to the Grand Canyon. The dynamic cracking, dropping, and thrusting of the earth’s crust exposed colorful layers of rocks dating back to the age of the dinosaurs and older. Faulting helped create the many cinder cones and lava flows in the area. Erosion has since carved dramatic canyons, and more recently, windblown sand has accumulated in eddies, forming soft dunes.
This structural diversity is enriched by the Virgin River and its tributaries, ribbons of water allowing for a lush biodiversity in the desert.