These are locomotives of the Chicago, Milwaukee, St. Paul and Pacific Railroad, often referred to as the "Milwaukee Road". The Milwaukee was acquired by the Soo Line in 1985 and the Soo subsequently became part of the Canadian Pacific Railway.
Milwaukee Road steam locomotives were organized into classes by wheel arrangement. Additional suffixes, where used indicated:
Class A was the 4-4-2 type.
Class B was for Vauclain compound 4-6-0s built by Baldwin Locomotive Works. Most were rebuilt as simple engines, those not rebuilt were scrapped in the late 1920s.
Class C was the 2-8-0 type.
Class D was the 0-8-0 type.
Class E was reserved for the electric locomotives.
Class F covered the 4-6-2 and 4-6-4 types.
Class G was the simple 4-6-0 type, some of which were rebuilt from class B compounds.
Class H covered the 4-4-0 "American" type.
Class I covered the 0-6-0 switcher types.
Class J covered 0-4-0 switchers.
Class K comprised 2-6-2 "Prairie" locomotives.
Class L was for 2-8-2 "Mikado" locomotives.
Class M was for the 2-6-0 type.
Class N consisted of articulated locomotives of 2-6-6-2 arrangement.
Class S were 4-8-4 "Northern" locomotives.
Class X covered Lima Shay's.
The Milwaukee Road was one of the most electrified railroads in the United States. The system used was 3,000 volt DC overhead line.
Only six Milwaukee Road steam locomotives survive:
In addition, the tender from a class S2 locomotive also survives in Ingomar, Montana.