Project Blue Book Case #1243. On June 1, 1952, a bright object was observed over Rapid City, South Dakota — home to Ellsworth Air Force Base, a major Strategic Air Command installation that hosted B-36 intercontinental bombers. Rapid City sits at the edge of the Black Hills, with the Great Plains stretching endlessly to the east.
Ellsworth's bombers were part of SAC's nuclear strike force, and the base's airspace was under constant surveillance. The proximity of Mount Rushmore and the Pine Ridge Indian Reservation added geographic distinction to the setting. The case was classified "Unknown."