Historic photo from the internet! Western Pacific Railroad 4-6-6-4 articulated Challenger type steam locomotive. Elko Nevada circa 1940's era.

A good strong heavy duty steam locomotive used by various North American railroads for pulling heavy drag freights or assisting other trains over heavy mountain grades, were these huge articulated Challenger type steam locomotives with the 4-6-6-4 wheel arrangement.

This Western Pacific Railroad Alco 4-6-6-4 Challenger locomotive, was photographed at Elko Nevada during the 1940's. The ground proboubly shook when these mechanical monsters came through with heavy freight trains coupled on.