• Knightia eocaena mass mortality

    Fossil Butte

    National Monument Wyoming


Beaver ponds are located near springs that surface at the contact of the Green River and Wasatch Formations.  The ponds provide ideal habitat for amphibians like this northern leopard frog.

Northern leopard frog.

NPS photo by Clay Kyte

Only three species of amphibians are documented: the Utah tiger salamander (Ambystoma tigrinum), chorus frog (Pseudacris triseriata maculata), and northern leopard frog (Rana pipiens).

Did You Know?

Diplomystus dentatus, NPS photo of Fossil Country Museum specimen

Railroad workers played a major role in the discovery of fossils from the Green River Formation. In the late 1860's, Union Pacific workers uncovered the first major fossil fish beds (Lake Gosiute) near the town of Green River, Wyoming.