Ground-water conditions in the Navajo Sandstone in the central Virgin River basin, Utah

The central Virgin River basin, Utah, includes about 1,000 square miles (2,600 square kilometers) in the drainage basin of the Virgin River downstream from the Hurricane Cliffs. The Navajo Sandstone of Late Triassic(?) and Jurassic age crops out in 234 square miles (606 square kilometers) of the basin and underlies younger rocks in about 450 square miles (1,200 square kilometers) of the basin.