Morris Reservoir, reservoir in the San Gabriel Mountains, Los Angeles County, California, United States

Morris Reservoir is a storage lake in California located in the San Gabriel Mountains and surrounded by trees and rocky slopes. The water is held back by a concrete dam completed in 1935 that rises more than 200 feet (about 60 meters) above the creek bed.

Morris Dam was completed in 1935 to secure the region's water supply and control flooding. From the 1940s through the 1990s, the area served as a Naval Weapons Test Site for developing and testing torpedoes, missiles, and naval weapons.

The reservoir's name is not tied to a founding family in the sources; it is linked to Morris Dam, completed in 1935. From World War II through the 1990s the reservoir and its slopes formed the Morris Reservoir Naval Weapons Test Site, set up by Caltech for the Navy, where torpedoes, bombs and the submarine-launched Polaris missile were developed. The site was transferred to the Los Angeles County Department of Public Works in 1995.

Morris Reservoir is located about five miles north of Azusa along California Route 39 and is easy to reach. Bring sturdy shoes and your own supplies, as only minimal facilities are available on site.

Caltech opened the reservoir substation because its main Naval Ordnance Test Station at China Lake was a dry lake in the Mojave Desert; the San Gabriel site near campus allowed work on submarine-launched systems such as the Polaris rocket, the first ballistic missile launchable from submerged submarines. The reservoir passed to the Los Angeles County Department of Public Works in 1995.