Glen Canyon - the western end of Glen Canyon

The western end of Glen Canyon is located near Lees Ferry. The Colorado River canyon cuts through a large structural fold in the rock, called the Echo Cliffs Monocline, exposing shales of the Chinle Formation (stratigraphically beneath the sandstones of the Glen Canyon Group exposed upriver in Glen Canyon). The Chinle Formation consists of shale, mudstone and sandstone formed from muddy sediments deposited by river systems (fluvial environments) in a continental setting in the Late Triassic Period. The Chinle contains fossil wood, dinosaur bones, and fossil animal tracks.