Clark's Mountain is a summit in Clatsop County, Oregon. It is named for William Clark (1770–1838), who during the Lewis and Clark Expedition, likely viewed the summit from the vicinity of Cape Disappointment. It is located in Ecola State Park, 2.4 km (1.5 mi) northeast of Tillamook Head, 0.8 km (0.5 mi) south of West Point, 3.5 km (2.2 mi) southwest of Seaside, Oregon. The summit has an elevation of 355 metres (1,165 ft).