The Bull Run Hydroelectric Project was a Portland General Electric (PGE) development in the Sandy River basin in the U.S. state of Oregon.

Originally built between 1908 and 1912 near the town of Bull Run, it supplied hydroelectric power for the Portland area for nearly a century, until it was removed in 2007 and 2008.

The project used a system of canals, tunnels, wood box flumes and diversion dams to feed a remote storage reservoir and powerhouse.

[3] The 140-acre (57 ha) lake acted as a reservoir for the powerhouse, which was completed and put into operation in 1912, the same year that the MHR&P merged with Portland Railway, Light and Power Company (PRL&P), the predecessor of PGE.

[1] The Marmot Dam included a fish ladder to allow migration of salmon and steelhead; however it performed poorly at first and required frequent upgrades and maintenance, which continued into the 1990s.

[6] PGE sought and received initial approval for the project from the Federal Energy Regulatory Commission (FERC) in 1999.

PGE later employed RESOLVE, a non-profit dispute resolution organization, to help develop a detailed consensus plan among the interested parties.

In 2006, PGE requested special approval of the decommissioning from the National Marine Fisheries Service, because of the project's potential impact on coho salmon.

The final review was conducted by the United States Army Corps of Engineers, which granted approval for the decommissioning on May 21, 2007.

The event attracted 600 visitors, including a number of long-time employees of the facility whose stories were captured by an ongoing oral history project associated with the preservation effort.

The historic schoolhouse and park components of the site were conveyed to Trackers Earth, an environmental education organization.