Just across the Idaho border lies Fossil Butte National Monument in Kemmerer, Wyoming. This high altitude (6,500 to 8,000 feet) park covers 8,000 acres. The area is considered a high altitude desert high altitude desert ecosystem and the frost free period is less than sixty days. This relatively small park features numerous pronghorn, porcupine, jackrabbits, eagles, coyotes and mule deer that roam the park among the sagebrush and grassy areas. Many other plants and animals lie sandwiched in the multicolored layers (strata) of rock as this ancient limestone bed holds one of the richest natural collection of fossils in the world. Buried in rock matrices are the remains of plants and skeletons of fish, birds and even crocodiles.