Fossils of Lake Gosiute

FACT: Search for fossils at Lake Gosiute, and come along on a time-travel tour to understand the saga of our own Jurassic park.

It was called Lake Gosiute. Its size varied over time, but at different epochs it extended as far north as Pinedale, as far east as Rawlins, as far west as Lyman and as far south as Manila, Utah, according to geologists.

Before setting out to find the fossils of Lake Gosiute, come along on a time-travel tour to understand the saga of our own Jurassic park.

It starts 58 million years ago. The creation of this area began during a time when all the continents were still attached. A mountain rose out of the flat plateau at Rawlins and cut off the drainage. Keep in mind, this entire area was only about 1,000 feet above sea level. With the lake in place, an ecosystem was born.

The environment was tropical. Lots of dinosaurs roamed the shores, and strange creatures lived in the lake. To give you an idea of how radically different it was, consider that it takes about 25 feet of dense vegetation to make one foot of coal. Now consider how much coal there is compared with the current vegetation.

Over time, the climate changed. Certain mammals gave way to others, but fossils were already being created.

Many vegetation type fossils can be found to the east of Rock Springs. To the west are more basic, oceanic creatures.

Now, how do you find the fossils of Sweetwater County, and where are the best sites and displays? Start at Western Wyoming Community College, which has the best collection of dinosaurs on I-80 from San Francisco to Chicago.

Also, don’t forget about Fossil Butte on Highway 30, just east of Kemmerer. The Butte has an interpretive visitor center with some great exhibits and tours.

For More Information
Fossils of Lake Gosciute visit www.ww.cc.wy.edu 
Fossil Buttes National Monument visit www.fws.gov/seedskadee