The dredge head of the Army Corps of Engineers Dredge Biddle at the mouth of the Columbia River. This huge machine had the capacity to operate at 4 knots, load 3000 cubic yards in 40 minutes and discharge the same in 20 minutes.

Image ID: fish6621, NOAA's Historic Fisheries Collection
Photo Date: 1970 August
Credit: NMFS/Northwest Fisheries Science Center; Pacific Northwest Collection

Category: Historic Fisheries/Salmon/

• High Resolution Photo Available