Wyoming's Aquarium in Stone

Fossil Butte National Monument can be found about 10 miles west of Kemmerer. It's known as Wyoming's Aquarium in Stone. It lies in what was once one of the three Great Lakes of Wyoming, Utah and Colorado -- Lake Gosiute, Lake Uinta and Fossil Lake. All are gone today, but they left behind a wealth of fossils in lake sediments that turned into rock known as the Green River formation. The fossils are among the most perfectly preserved remains of ancient animals and plant life in the world. Some of the most extraordinary came from Fossil Lake. Fossil Butte National Monument preserve the butte and its invaluable, fascinating record of the past.

The scene 50 million years ago (as reported by the National Park Service brochure), during the Eocene Epoch of the Cenozoic Era, was quite different from today. Fossil Lake was 50 miles long and 20 miles wide at its maximum point, nestled among mountains in a lush green forest of palms, figs, cypress, and other subtropical trees and shrubs. Willows, beeches, oaks, maples, and ferns grew on the lower slopes, and on the cool mountain sides was a spruce and fir forest. In an around the warm waters of the lake, animal life was diverse and abundant.

A broad range of fish inhabited the tributaries, shallows and deep water of Fossil Lake during its life of more than two million years. Gars, paddlefish, bowfins and stingrays, though they may appear primitive to some, still survive today, as do herring, perch and mooneyes. The lakeshore was alive with crocodiles and turtles; insects, dog-sized horses, and early primates inhabited the land; birds and bats mastered the air.

This vibrant scene is gone now because of profound climate change. But the site will be protected at Fossil Butte National Monument,