O'Neill Dam

O'Neill Dam is an embankment structure that crosses the San Luis Creek valley in California and creates a large reservoir with multiple shoreline areas. The water body provides space for various water-based activities and is fed through irrigation channels from larger waterways.

The dam was constructed between 1963 and 1967 by the Bureau of Reclamation as part of a major irrigation project for the valley. Its completion marked an important step in moving water from northern sources to agricultural areas in the south.

The forebay serves as a recreation hub for people from the surrounding region who come for fishing, boating, and weekend outings. It has become a regular gathering place for water lovers and families seeking outdoor activities.

The dam is located roughly 20 kilometers west of Los Banos along a major highway and is easily accessible by car. Visitors should note that the location sits in a dry region and water levels vary seasonally throughout the year.

The dam is managed by a special spillway with a circular funnel design that looks like a giant bathtub drain when in operation. This unusual system regulates water flow in an automatic way without requiring moving parts to function.

Location: Merced County

GPS coordinates: 37.08050,-121.04700

Latest update: December 14, 2025 09:46