Wyoming’s Geologic History
by Paul Meiman
| The breathtaking views we see in Wyoming today are a product of landscapes that have taken hundreds of millions of years to create. In other words, Wyoming hasn’t always looked the way it does today. |
| At times it has been covered by sea water. Other times, huge freshwater lakes covered up to a quarter of what is now Wyoming. About three hundred million years before bison and antelope roamed what is now Wyoming rangeland, massive swamps and lagoons were home to huge dragonflies with thirty inch wingspans. |
| Mountains have come and gone and come back again. Valleys between mountain ranges have filled with so much sediment that only the very tops of the mountains were sticking out. Then, the erosive action of streams and rivers emptied those valleys out again. Volcanic activity and glaciers have further modified Wyoming landscapes producing "U" shaped valleys and lakes or potholes. |
| Like all of us, Wyoming is a product of its upbringing. Together with climate, Wyoming’s geologic history is responsible for producing the mix of rangelands and forests that we see today. From the University of Wyoming Cooperative Extension Service, I’m Paul Meiman. |