This is a gravity dam that is 234 feet thick at it's base. It goes into the cliffs on each side 150 feet, also it goes 60 feet below the river bed. Due to being a federal dam, I was not able to shoot any photos inside it, but it was very cool in there literally, 50 degrees. The tunnels are about 5 feet wide, maybe 7 feet high. Big enough to drive a Volkswagen Beetle through, good luck turning the corners though. It took 320 million tons of cement to make this beast. It has 121 monoliths from side to side. Standing on a platform right above the wall was about 110 feet above the river. They have seen water get as high as 96 out of the 100 foot high wall. That was in 1972. This was started in 1947, and finished in 1951.