The reservoir was formed by damming Los Gatos Creek, and the dam was finished in 1934. The name comes from a railroad flag stop: farmer Albert August Vollmer asked the Southern Pacific for a stop and named it Vasona, after his childhood pony.
The park has pedal boats, kayaking and paddleboarding (no swimming), the Youth Science Institute’s nature center, which opened in 1980, and the Fantasy of Lights, held since 1999. It adjoins the town’s Oak Meadow Park.