Northern Pacific class Z-5 number 5000 hauls a freight train at track speed on the Yellowstone Division circa 1938. Photo by Ed Overlie, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, freight train.

Northern Pacific steam locomotive 5000 from a company roster book in 1928. Number 5000 is a class Z-5 built by Alco-Schenectady in 1928. J.M. Fredrickson collection. Number 5000 is documented in a booklet titled "The Worlds' Largest Steam Locomotive". Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 5000 on display at Mandan, North Dakota, in 1928. Number 5000 is a class Z-5 built by Alco-Schenectady in 1928. J.M. Fredrickson collection. Number 5000 is on public display in Mandan as the "World's Largest Steam Locomotive". Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 500 with a snow plow, circa 1898. Number 500 is a class D-3 built by Baldwin in 1889. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 500 poses with crew, circa 1890. Number 500 (old number series) is a class M built by Baldwin in 1886 for service on the Stampede Pass switchbacks. Renumbered to No. 1. in 1897. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 50 awaits its next assignment, circa 1935. Number 50 is a class F-1 built by Baldwin in 1888. J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo

Northern Pacific steam locomotive 50 at Tacoma, Washington, on March 30, 1936. Number 50, a class F-1 built by Baldwin in 1888, is parked on a radial track at the Tacoma roundhouse. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 50 at Tacoma, Washington, on February 29, 1936. Number 50, a class F-1 built by Baldwin in 1888, is parked on a radial track at the Tacoma roundhouse. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 50 at Tacoma, Washington, on March 30, 1936. Number 50, a class F-1 built by Baldwin in 1888, is parked on a radial track at the Tacoma roundhouse. Photo by Herman Hunt, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roundhouse

Northern Pacific steam locomotive 490 on June 09, 1916. Number 490 is a class D-3 built by Baldwin in 1889. Photo by Charles R. Iles, J.M. Fredrickson collection. Other Subject Classes: steam locomotive, roster photo