The 4-6-6-4 Challenger Steam locomotive, Steam trains photography, Locomotive

Union Pacific Railroad No. 3983 4-6-6-4 Challenger Type Steam Locomotive Photo

Denver & Rio Grande Western Railroad - D&RGW Challenger Cl…

Northern Pacific Railroad Challenger Steam Engine 5134 4-6-6-4 8x10 Photograph

Scenic railroads, Locomotive, Train museum

Union Pacific Challenger No. 3985

4-6-6-4/Gallery, Locomotive Wiki

DH 4-6-6-4 #1502 - Delaware & Hudson

UP locomotive, engine number 3999, engine type 4-6-6-4 - Photographs - Western History - Denver Public Library Special Collections and Digital Archives Digital Collections

America's Steam Trains-Challenger 3985-The Worlds Largest Operating Steam Locomotive : Jarrett, Les: Movies & TV

Union Pacific 4-6-6-4 Challenger Locomotives in the USA

Union Pacific challenger 4-6-6-4 Steam Locomotive Chart

Union Pacific 3977 4-6-6-4 Challenger Class Live Steam