Bureau of Reclamation

West Canal, Columbia Basin Project, of which the Grand Coulee Dam is a part. This photograph was taken at the site of the Dry Coulee Siphon No. 1 and shows final grading preparatory to the building of the siphon.

Potholes Dam, Columbia Basin Project. Photograph shows excavation to bedrock for foundation of the earth and rock dam. The dam will be the fourth longest in the U. S.

T. E. Connelly construction camp at outlet portal of 10,000 foot Bacon Tunnel. Main Canal will follow natural channel in distance. This work is on the Columbia Basin Project and Grand Coulee Dam project.

Main Canal, Columbia Basin Project, of which the Grand Coulee Dam is a part. This picture was taken from the inlet portal of the Bacon Tunnel. A siphon will cross the Coulee below and connect the Main Canal open section (background) with tunnel.

Bacon Tunnel, Columbia Basin Project and Grand Coulee Dam project. This picture shows a typical drilling scene on the 10,000 foot Bacon Tunnel, which pierces a basalt barrier. Finished tunnel will be 23 feet in diameter.

Long Lake Dam, Columbia Basin Project, Grand Coulee Dam Project, shows excavation to bedrock on the 1,900-foot earth and rock dam which will save several miles of costly canal construction.

Main Canal, Columbia Basin Project, of which the Grand Coulee Dam is a part. This is part of the southerly six and one half mile section of the Main Canal. Canal must be lined with concrete before it can be used.

Looking into the Grand Coulee Dam pumping plant foundation. The world's largest pumps and electric motors will be installed here to serve irrigation system.

Assembling war-built temporary houses to accommodate workers at Grand Coulee Dam. Dwellings came from Vancouver, Washington housing project for shipyard workers.

Floating caisson for spillway repair work at Grand Coulee Dam being assembled in circular drydock. Excavation of river channel in background.