Center, or river, section enclosed by crib-type coffers, up- and down- stream, and sections "D"E" and "G" of steel cofferdam. high and low placing trestles extending out from east side in foreground. Block 40 in center."Ice Dam" to left of central foreground.
The completed cofferdams allowed complete diversion of the Columbia River from the eastern and central portions of the Grand Coulee Dam construction site. The diverted river flowed through the diversion channels on the Westside of the construction project.