Photograph of what looks like a school field trip exploring plant fossil beds at the head of Grand Coulee. Automobiles and clothing date the photograph as circa 1920-1930's.
Spillways -- Design and construction; Grand Coulee Dam (Wash.);Hydroelectric power plants -- Washington (State);Dams -- United States -- Design and construction.
TRASH RACKS (HYDRAULIC STRUCTURES); Grand Coulee Dam (Wash.);Hydroelectric power plants -- Washington (State);Dams -- United States -- Design and construction.
Trash Racks on the upstream side of Grand Coulee Dam. The trash racks were to keep floating debris from entering the penstocks and damaging the turbines.