This 9,117-acre rocket test facility, once operated by Lockheed, is now undergoing remediation and restoration. Potrero Canyon, and nearby Laborde Canyon, were developed by the Grand Central Rocket Company in the 1960s, for testing solid rocket motors and propellants. Portions of the property were leased to other companies for testing other weapons. Activities were principally at 14 sites, and continued into the 1980s. Most of the site has been turned over to the State of California, to be maintained as open space. Lockheed Martin, which, as Lockheed, acquired the Grand Central Rocket Company in 1960, maintains ownership of a small portion of the property.