The Submerged History of Monticello: California’s Lost Town Beneath Lake Berryessa
In 1956, the historic community of Monticello, California, was intentionally flooded to create a massive freshwater reservoir, leaving the town’s entire infrastructure submerged beneath Lake Berryessa. Today, the sunken remains of the agricultural settlement—including its roadways, bridge structures, and building foundations—continue to lie at the bottom of the lake in eastern Napa County.
The intentional flooding of Monticello was the outcome of a major water storage project initiated to support agriculture and urban development in the region. Construction of the Monticello Dam along Putah Creek began in the mid-1950s, forcing the displacement of local residents and the clearing of farms, homes, and public buildings throughout the Berryessa Valley.
Despite being submerged for decades, structural elements of the town remain preserved below the water’s surface. Underwater surveys and historical records confirm several key features that still exist beneath the lake:
- Street Grids: The original paved roads and street layouts that once routed traffic through Monticello.
- Structural Foundations: Concrete basements, stone foundations, and remnants of residential and commercial property.
- Historical Landmarks: The large stone arch Putah Creek Bridge, which was left intact before the valley was inundated.
During periods of severe drought when water levels in Lake Berryessa drop significantly, portions of Monticello’s long-lost physical footprint briefly become visible again. The creation of the reservoir permanently altered the landscape, turning a once-thriving agricultural valley into one of the largest bodies of water in California.
Key Points
- Monticello, California was submerged in 1956 to build Lake Berryessa.
- The town was flooded following the completion of the Monticello Dam on Putah Creek.
- Original streets, foundations, and a historic stone bridge still rest underwater.
- Low water levels during severe droughts occasionally reveal the submerged town’s ruins.