Prototype Lamprey-Passage Structure
Underwater construction and welding experts were brought in by the prime contractor, Marine Industrial Construction of Wilsonville, Ore., to modify the existing fish ladder entrance sill. These skilled divers worked under 20-30 feet of water, removing concrete and rebar to allow precise fitting of the new prototype lamprey-passage structure.

Download Image: Full Size (1.65 MB)
Tags: lamprey, McNary
Photo by: U.S. Army Corps of Engineers - Terry Zerb  |  VIRIN: 140217-A-CE999-980.JPG