In this TOP SECRET memo from 1944 addressed to the Commander of Naval Air Bases, Eleventh Naval District, San Diego the plans for a target specifically for “special bombing” tests at Salton Sea are laid out. “Special bombing” refers to testing the aeroballistics of atomic bomb shapes and forms as part of the development of the atomic bomb. The memo points out that Captain W.S. Parsons, K.B. Brode and Lieutenants T.C. Allen and J.P. Ruhman all visited “Sandy Beach” (code name for the Salton Sea Test Base) to inspect the site to construct a bombing target.
You can see the code-name for the Salton Sea Test Base, “Sandy Beach” (the actual original name for the beach area where the Naval Station was constructed) hand written in the upper right.