Marble Mountain-Trout Creek Hill is a volcanic field in Washington that includes vents such as Trout Creek Hill and West Crater. Trout Creek Hill is a small Pleistocene basaltic shield volcano that, about 340,000 years ago, produced a lava flow extending roughly 20 kilometers to the southeast and briefly damming the Columbia River. West Crater, also in southern Washington, is a small andesitic lava dome with associated lava flows. Together these features reflect the area's varied volcanic activity and its direct impact on the surrounding landscape.