PLUMBBOB/BOLTZMANN - 5/28/57 - BOLTZMANN fireball, May 28, 1957, photographed 11 miles from ground zero. Photo courtesy of National Nuclear Security Administration / Nevada Site Office (08/21/2007), [435337470] . Denver Public Library Digital Collections, accessed 10/02/2026, https://digital.denverlibrary.org/nodes/view/798585