Lake Berryessa

Lake Berryessa is a large reservoir in Napa County, California, formed by the impoundment of Putah Creek behind Monticello Dam. It is a prominent regional recreational lake and a local water-supply reservoir.

The reservoir offers boating, fishing, camping and shoreline recreation with multiple access points and marinas. A visually distinctive engineering feature is the dam’s bell-mouth spillway, commonly known as the “Glory Hole,” which functions as the lake’s principal overflow when levels are high.

Monticello Dam was constructed in the mid-20th century and the reservoir was created to store water for regional irrigation and municipal use; the facility also became a recreational resource as access and marinas developed. The dam was completed in 1957.

Lake Berryessa lies in Napa County in northern California, set within a largely rural and hilly landscape and accessed from several local roads and communities that serve the lake’s recreation sites.

• Dam and creation date: Created by the Monticello Dam, which was completed in 1957, the reservoir is a major water body in Napa County used for recreation and water supply.
• Spillway feature: The dam includes a bell-mouth spillway popularly called the "Glory Hole," which is visible when the reservoir reaches high levels.

What to See #

• Monticello Dam (and spillway): Monticello Dam blocks Putah Creek and creates the reservoir; the dam's bell-mouth spillway is a noted engineering feature and local landmark.