Elm Grove, Wisconsin
The trackage was originally developed in 1864 by the Milwaukee and St. Paul Railroad Company, which later became the Chicago Milwaukee St. Paul and Pacific Railroad Company. Soo Line acquired the line in 1985.
I'm not sure what the line on the map is referencing, but the abandoned line being discussed here is just to the east, shown on the map branching off at Elm Grove and ending just north of Krueger Park.
Is the land for sale?