The Monticello Dam, construction 1953 to 1957, was built by the U.S. Department of Reclamation. It is named after the small town of Monticello that has been below the waters of the lake for over 60 years now. The dam was built in a valley between the Vaca Mountains in Napa County which traps and contains the water of Putah Creek creating Lake Berryessa (it took five years to fill the lake). Lake Berryessa is the second largest reservoir in California with Lake Shasta claiming the top position. The dam, sitting on a 239 feet high base the dam extends upward for another 304 feet (total 543 feet high) and 1,023 feet wide and begins at the base at 100 feet thick tapering as it reaches the top. While the dam isn’t as impressive as let’s say Hoover Dam, what really draws the attention at this 62 year old dam is the “Glory Hole.” The Glory Hole is an uncontrolled spillway that is shaped like a giant funnel. At the lake level the Glory Hole has an opening of 72 feet in diameter and at the base it has a diameter of 15 feet. When the water spills over the lips of the Glory Hole it falls to the bottom and into Putah Creek. When the lake level plunges the ruins of the town of Monticello can be seen, I can only remember this happening once since 1971 (when our family moved north). The area around the Glory Hole is off limits and I have heard of one person crazy enough to swim near it and get washed over the edge and fall to their death.