Project Blue Book Case #2302. On December 28, 1952, a bright object was observed over Marysville, California — a Sacramento Valley community adjacent to what would become Beale Air Force Base, future home of the SR-71 Blackbird reconnaissance aircraft and the nation's only operational U-2 squadron. In 1952, the former Camp Beale was being converted to an Air Force installation.
Marysville sits at the confluence of the Yuba and Feather rivers, at the northern end of the Sacramento Valley. McClellan AFB near Sacramento was the nearest major active installation. The case was classified "Unknown."