Little did we know what treasures were buried when the John Martin Reservoir in Bent County, southeastern Colorado, was constructed in 1948 for flood and water resource management of the Arkansas River. When full, the reservoir is the largest body of water in the region. In 2004-2005 , the region experienced a drought that nearly drained the reservoir entirely. Due to the drought, nearly 300 dinosaur and other vertebrate tracks were discovered in dry portions of the reservoir bed. Most of the tracks are attributed to the ichnogenus Caririchnium, which is thought to have been made by an ornithopod, aka duckbill-type dinosaur. An ichnogenus is a genus that is only known from the trace fossil, such as a track, burrowing, trail, and etc. Caririchnium is characterized by three broad toes and a large heel. Other tracks found include the ichnogenus Magnoavipes, a track possibly made by a theropod or meat-eating dinosaur, numerous crocodile swimming tracks, and the first-ever discovered pterosaur, a flying reptile, tracks from the region.