Dinosaur Quarry

This is a close look at a portion of the exposed wall inside the Dinosaur Quarry building. The steeply dipping surface, parallel with the bedding plane of the Morrison Formation, has been excavated to expose about 1,600 dinosaur bones in their natural position. The congregation of all these bones, some still articulated (connected), was the result of bones and bodies being carried from overbank deposits during flood stages, and deposited into a main river channel where they were buried in sand and gravel.

Print No. A01NW-44-12

Morrison Formation

The steeply-tilted beds in this view just east of the Dinosaur Quarry belong to the Upper Jurassic Morrison Formation. This ridgeline follows the same strata that are exposed in the Dinosaur Quarry. The various hues of the Morrison Formation, including pink, lavender, and green, are caused by different oxides in the deposit.

Print No. A01NW-46-4

Harpers Corner Trail

This is the view east from the end of Harpers Corner Trail on the Colorado side of the monument. Here, the Green River carves the canyon in the upper left. The Yampa River is visible in the upper right and joins the Green River behind Steamboat Rock (the folded strata in the center of the image). The folding was the result of a thrust fault, which angles beneath where this image was taken. The limestone and shale here atop Harpers Corner has been uplifted about 3,000 feet (910 meters) along this fault.

Print No. A01NW-44-4

Split Mountain View

From the Split Mountain picnic area, this is the view across the Green River. The beds in this image are primarily Jurassic age, with younger beds progressively above and to the right. This sequence of exposed beds is part of a monocline, which has exposed strata from as old as the Pennsylvanian Period in the core of the fold, to as young as the Cretaceous Period around the periphery. This upwarping occurred during the Laramide Orogeny (mountain-building event), between 45 million and 70 million years ago, which included the building of the Uinta Mountains in northern Utah and the rise of the modern Rocky Mountains further to the east.

Print No. A01NW-46-10