Sheep Mountain

The panel never mentions the river that runs straight through the fold. The Bighorn River crosses Sheep Mountain at right angles to its crest, in a canyon about a thousand feet deep known as Sheep Mountain or Black Canyon, and the cut lays bare the Paleozoic rocks of the fold's core. Geologists describe it as cored by Precambrian basement pushed up along a reverse fault, running parallel to the Bighorn uplift twenty miles east. Stanford researchers mapped it by lidar in 2007, and the Spence oil field lies along its eastern foot.

What the plaque says

Sheep Mountain The prominent hill to the east is known as Sheep Mountain. It is the surface expression of an upward fold in the earths crust that geologists refer to as an anticline. Sheep Mountain is a text book example of an anticline fold. It is 15 miles long and the involved rock formations, which were originally horizontal, have been bent and uplifted over 1000 feet. The surface sedimentary rock formations that are exposed in the fold, range in age from 66-360 million years. Anticlines form when deep seated, compressive forces within the earth's crust, squeeze and shorten the crust The geologic event which resulted in the creation of Sheep Mountain Anticline, along with many other anticlines in the Big Horn Basin began approximately 66 million years ago. This is the same time period during which dinosaurs became extinct. The present Sheep Mountain has evolved over the past 3 million years. It resulted from down cutting of the land surface by rivers and streams and the removal of much of the original basin fill sediment. Provided by the Big Horn Industrial Development Corporation

Where it stands

More markers nearby

• The Mormon Colonists — 17 mi
• McCullough Peaks Wild Horses — 18 mi
• Shortcut to the Goldfields — 18 mi
• Sidon Canal — 18 mi