Grand Coulee Dam

For many years this was the largest concrete structure ever built. I think it has since been surpassed (or will be soon). It was built in the 1930's, though it may not have been completed until the early 1940's. I have been told that the water table over most of eastern and central Washington was raised significantly as a result of the resevoir created by this dam.

Next: GPS at 47°N 118°W
Journal: 7 May 2000: Grand Coulee Dam and 47°N 118°W