View of Lake Powell's south shore from the Ferry route between Wahweap Marina (near Page, Arizona) and Rainbow Bridge National Monument in Utah. Approaching the flooded canyon in Navajo Sandstone that leads to Rainbow Bridge National Monument. (Click here to take a detour to Rainbow Bridge National Monument.) Navajo Mountain in the distance is located on the Navajo Reservation in northern Arizona. Navajo Mountain formed from Tertiary igneous intrusions (called laccoliths) that pushed up the sedimentary formations to for a dome-shaped mountain (Eldridge, 2010). Other mountain ranges in the region around Glen Canyon National Recreation Area that formed in a similar manner include the Henry Mountains and Abajo Mountains in southern Utah.