River Mill Hydroelectric Project, hydroelectric dam and powerhouse in Clackamas County, Oregon, United States

The River Mill Hydroelectric Project is a dam and power station on the Clackamas River in Oregon that has been generating electricity for over a century. The structure was completed in 1911 and uses a special Ambursen design with concrete elements that support one another.

The power station was built in 1911 by Portland Railway, Light and Power Company and was one of the first major hydroelectric projects in Oregon. The Ambursen design was innovative for its time and helped establish new standards for concrete dam construction.

The dam bears the name of its designer Nils F. Ambursen and is seen by locals as a landmark of their energy development. For the community, the structure represents a chapter in regional industrial growth and remains an active part of daily infrastructure.

The power station can be viewed from the east bank of the river and offers quiet paths for walking nearby. The best visits are on peaceful days when you can enjoy the sounds of flowing water and nature without distraction.

The structure is one of only three Ambursen dams on the west side of the Mississippi River and showcases a revolutionary concrete technique. This rare design feature makes it an important example of engineering history that influenced dam construction worldwide.