The distictive banding of the <a href="https://en.wikipedia.org/wiki/Morrison_Formation" class="extiw" title="w:Morrison Formation">Morrison Formation</a>, a group of rock layers that occur throughout <a href="https://en.wikipedia.org/wiki/Dinosaur_National_Monument" class="extiw" title="w:Dinosaur National Monument">Dinosaur National Monument</a>.  The formation originated as muds and sands laid down by ancient rivers, and some of its outcrops have been found to contain 150-million-year-old dinosaur fossils like those found at the monument's Dinosaur Quarry.
Photo by <a href="//commons.wikimedia.org/wiki/User:Moverton" title="User:Moverton">Michael Overton</a>.
CC BY-SA 2.5
Digital photograph