During an early railfan weekend, Cass Scenic Railroad Shays 4 and 5 lead a train up Cass Hill through Gum Curve on May 16, 1975. Photograph by more)

Cass Scenic Railroad Shays 2 and 5 lead a train of empty log cars on one of the railroad's early photographer's specials near Bald Knob on November 4, 1972. Photograph by more)

Westbound Penn Central freight train at Bay Junction in West Detroit, Michigan, on October 14, 1973. The large building at the left is General Motors' Cadillac plant. Photograph by more)

Westbound CSXT freight train with Tropicana orange juice cars led by Conrail power crossing the Thomas Viaduct over the Patapsco River at Relay, Maryland, on April 5, 1990. Photograph by more)

Two Milwaukee Road Hiawatha passenger trains at Chicago Union Station, circa 1950. Leading the train in the background is F7-class 4-6-4 no. 102. Photograph by more)

An eastbound Union Pacific freight train has just exited one of the Hermosa tunnels on Wyoming's Sherman Hill on August 17, 1957. Road power is 4-8-8-4 "Big Boy" no. 4019, assisted by 4-8-4 no. 82... (more)

A pair of Lehigh Valley Alco products led by C628 #640 lead an eastbound freight at Dupont, PA in July 1975. Photograph by more)

Rock Island E6 #630 switching at Chicago while E8 #660 rests in the background in this May 1973 scene. Photograph by more)

Green Bay & Western C424 #312 and company works on an eastbound freight at Tunnel City, WI in August 1975. Photograph by more)

Westbound freight train behind D&H 1216 at Waverly, NY in July 1975. Photograph by John F. Bjorklundmore)

Eastbound coal train with BN SD40-2 #7917 passing through New Salem, North Dakota in July 1980. Photograph by more)

Westbound Soo Line freight train at Hamel, Minnesota, in December 1974 with an A-B-B-B consist of F-units. The train has just left Minneapolis and is crossing over U.S. Highway 55. The photograph... (more)

Soo Line no. 397 taking a spin on the turntable at Shoreham Yard in Minneapolis, Minnesota, in August 1962. The locomotive was one of four center cab Baldwin DT-6-6-2000s acquired from the Duluth,... (more)

Eastbound Soo Line freight train crossing the St. Croix River at Somerset, Wisconsin, in October 1974. The photographer, Wallace W. Abbey worked for the Soo from 1959 to 1970 and designed its red ... (more)

Lehigh Valley power gathered at Sayre, PA in May 1973. Photograph by John F. Bjorklund and cou... (more)