The Cedar Mountain Formation in eastern Utah is a land-deposited sedimentary sequence from roughly 140 to 94 million years ago, lying between the Morrison and Naturita formations and in places below the Mancos Shale. First studied at Cedar Mountain by William Lee Stokes in 1944, it preserves rivers, lakes, ponds, flood plains, and later beds influenced by the approaching Western Interior Seaway. Usually divided into several members, it is especially important for paleontology: since sustained work began in the 1990s, it has become known as one of the world’s richest sources of Early Cretaceous dinosaur fossils, while also preserving evidence of broader vertebrate life and changing continental connections.