• Red cliffs descend into the water of Bighorn Canyon

    Bighorn Canyon

    National Recreation Area MT,WY

Geologic Story

Meanders of the river have eroded the Madison Limestone
The entrenched meanders of the Bighorn river having eroded (superimposed) down through the Madison Limestone
NPS
 

A Story of Change

Geology is the study of the Earth, its various landforms, rocks, and what has happened to them throughout the history of the planet. That’s a lot of history considering the Earth is four and a half billion years old. Much has been going on from rock formation, mountain building and erosion to volcanoes, asteroid impacts and plant and animal evolution. Sometimes many different processes are occurring and sometimes distinctly more of one than another. In any case, what we know comes from studying the rocks.

Our mountains and canyons are not forever. In the Bighorn Canyon and Bighorn Mountains we have basically had thousands of feet of sedimentary rocks form on top of an even older basement complex of igneous and metamorphic rocks. Those rocks were uplifted to form the Bighorn Mountains. The subsequent erosion carved the Bighorn Canyon. While the mountains and canyons will change very little during our lifetime, their lifetime of millions and millions of years is essentially a story of change.

Did You Know?

Aerial view of Bighorn Canyon

Long before the Bighorn River was tamed by the Yellowtail Dam, the roiling waters through the canyon were feared. During spring snowmelt, the water turned into a raging torrent, a combination of whirlpools, rapids, and eddies. Conversely, the river through the canyon had a reputation for being placid by late summer, when dry heat and lack of rainfall turned it into a sedate stream. More...