Steamboat Rock is a striking sandstone promontory in Dinosaur National Monument in northwestern Colorado, where the Green River leaves Lodore Canyon and enters Echo Park near the confluence with the Yampa River. This long, narrow ridge rises 6,074 feet and stands within a meander of the Green, making it one of the monument’s most recognizable landmarks. Geologically, it is composed mainly of Weber Sandstone from the Permian and Pennsylvanian, capped by a thin layer of Park City Formation. Its history is also tied to exploration: John Wesley Powell called it Echo Rock in 1875, while the name Steamboat Rock appeared on a 1941 U.S. Geological Survey map.