Rising mushroom cloud after detonation of a nuclear device, most likely at the Nevada Test Site in Nye County, Nevada. Photo credit: Atomic Energy Commission.
Provided quote by Dave Coons: "Three locomotives at dam site; Hoover Dam construction. Middle locomotive ex-LV&T locomotive. Used by 6 Companies, judging by square tender."
Arrow pointing to canyon where the Hoover Dam site is proposed. Inscription on card reads: "Boulder Can[y]on Dam Site. Reservoir site. Boulder Can[y]on - Colorado River Looking Down Stream. J. F. Perkins Photo."