Union Pacific Railroad steam locomotive number 4004 on display at Cheyenne, Wyoming on July 29, 1986. UP 4004 rests in a park at Cheyenne Wyoming in 1986. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive.

Union Pacific Railroad steam locomotive number 4004 on display at Cheyenne, Wyoming on July 29, 1986. UP 4004 rests in a park at Cheyenne Wyoming in 1986. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive.

Union Pacific Railroad steam locomotive number 4004 on display at Cheyenne, Wyoming on July 29, 1986. UP 4004 rests in a park at Cheyenne Wyoming in 1986. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive.

Union Pacific Railroad steam locomotive number 4004 on display at Cheyenne, Wyoming on July 29, 1986. UP 4004 rests in a park at Cheyenne Wyoming in 1986. Photo by J.M. Fredrickson. Other Subject Classes: steam locomotive.