• 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?

Pretty Eagle Point

The Crow Reservation may be the largest in the state of Montana at 2.2 million acres, but consider that when first established by treaty in 1851 it was over 38 million acres in size. In relative size it was once larger the current land area of Georgia, today it is about twice the size of Delaware. More...