Many people appreciate the stunning vistas of the Great Basin desert; understanding the region's geological past can provide a deeper way to know and admire this landscape. In The Great Basin Seafloor, Frank DeCourten immerses readers in a time when the Basin was covered by a vast ocean in which volcanoes exploded and sea life flourished. Written for a nontechnical audience, this book interprets the rock record left by more than 500 million years of oceanic activity, when mud and sand accumulated and solidified to produce today's Great Basin across parts of modern Utah, Nevada, and California. DeCourten deciphers clues within exposed slopes and canyons to reconstruct the vanished seafloor and its volcanic events and examines fossils to reveal once-thriving ancient marine communities. Supplemental material is available online to serve as a field guide for readers wishing to explore this ancient ocean themselves as they travel through the region.