McClellan AFB Annex

McLellan AFB Annex #1 ("McClellan Anx #1") was a military installation near McClellan Air Force Base in Contra Costa County, California, that was active from 28 November 1951 to 2 July 1956. Strategic Air Command operated an automatic tracking radar station (call sign "Sacramento Bomb Plot") just outside of the base at Whitney and Eastern avenues (38.6052°N, -121.42502°W).

Background
Colorado Spring's 206th Army Air Force Base Unit at the end of WWII had Radar Bomb Scoring detachments at Kansas City and Dallas and in 1946, RBS evaluated 888 simulated bomb runs on San Diego. By 1950,. RBS Detachment D was at "Fort George Wright, Spokane, Washington [with] Commander: Lt. John Jones". Detachment D moved* to near McClellan AFB c. September 1951 and was renamed Detachment 12 of the 3903rd Radar Bomb Scoring Squadron, then subsequently Detachment 4 of the 3933rd RBS Squadron before closing as an 11th RBSS Detachment 4 radar site in January 1962.

A second RBS detachment was established at Fort George Wright and in 1957, moved to Boise, Idaho. In 1961, a Fort Stevens RBS detachment also moved to Boise.