The Virgin River in southwestern Utah is a major tributary of the Colorado River, and while it's erosional feats can't match that of the larger stream, they are significant nonetheless. While only about 162 miles long, the Virgin's handiwork can be seen in the canyon it has carved through Zion National Park, and the spectacular gorge it created when cutting through the Beaver Dam Mountains as it dropped down from the Colorado Plateau to the Mojave Desert.
The layers of rock exposed in Zion National Park are part of the Grand Staircase of sedimentary deposits of the Colorado Plateau that ultimately reach back in time over several billion years. The rocks exposed in Zion are much younger than that, having been laid down over the last 230 million years, or so. The oldest layers exposed in Zion were accumulating while dinosaurs walked the Earth.
Draining an arid watershed, the flow in the river can change drastically with changes in rainfall. On September 9th of this year the flow in the river increased from a rate of 174 cubic feet per second to over 4,700 cubic feet per second in just a matter of hours as rain along fell along the upper reaches. The erosive power of a change of that magnitude in such a short span of time explains how the Virgin was able to carve through the rock walls of Zion Canyon.
Zion National Park is one of the most visited national parks in the United States, greeting almost 3 million visitors annually.
This photo was taken with a Canon EF 17-40 mm f/4L USM lens zoomed to 17 mm on a Canon EOS 5D Mk III. The exposure was set to 1/350 sec at f/8.0 and ISO 800.