Fossil Butte National Monument

Fossil Butte National Monument is a protected area by the type of National Monuments in the southwest of the U.S. state of Wyoming. It preserves a fossil site, the Fossil Lake, from the Eocene epoch, about 50 million years ago.

The reserve was established in 1972 after the deposit explored in the 1870s and finds were marketed commercially for several decades. It is administered by the National Park Service.

Description

The reserve is located in Lincoln County, about 25 km west of Kemmerer. In the Eocene, about 50 million years ago, here was one of the three large lakes landscapes that were found from this period in the western United States. The climatic conditions at the time remember the current sub-tropical Florida.

The fossils consist almost exclusively of aquatic life forms, predominantly fish ( eg Notogoneus osculus ), next to crocodiles, soft-shelled turtles, two types of bats, dragonflies and some other species. The findings are incorporated into the Green River Formation, sedimentary rocks of the Great Lakes landscapes, consisting of sandstone and siltstone with an embedded coal and oil shale. The particularly interesting layers to be superimposed limestone and dolomite, which are found here in such a fine composition that they have received not only bone structures, but also soft tissues of the fossil fauna. The best-preserved finds are in the so-called 18- inch layer, a layer of limestone.

During the construction of the transcontinental railroad in the Rocky Mountains, the colonization of the West reached the so far only sporadically crossed by settlers treks region. In the 1870s, the near-surface coal was opened to supply the railroad. The miners made ​​the first fossil record. The fossil deposits were exploited commercially Between about 1900 and 1937 and sold the fossils to museums and private collectors around the world.