The Clackamas River is an approximately 83-mile (134 km) tributary of the Willamette River in northwestern Oregon, in the United States. Draining an area of about 940 square miles (2,435 km2), the Clackamas flows through mostly forested and rugged mountainous terrain in its upper reaches, and passes agricultural and urban areas in its lower third.
The river rises in eastern Marion County, about 55 miles (89 km) east-southeast of Salem. The headwaters are on the slopes of Olallie Butte in the Mount Hood National Forest, about 10 miles (16 km) north of Mount Jefferson, at an elevation of 4,90...
Click any point for details. Sections without stored geometry are drawn as straight put-in → take-out lines — actual courses follow the river.