Harlowton's switching demands eventually exceeded the capabilities of the ES-2, which was replaced in 1951 by a single GE Freight Motor (later reclassed ES-3) instead; thus from the 1950s to the 1970s the ES-2s were normally used only in the greater Butte area, in which the Deer Lodge shops were also located.

Engineers liked them due to their rapid throttle response, preferring them over diesels which were slower to transition and accelerate.

Their simple nature made them easy to service, and the units seldom needed major attention.

Few changes were made to them over the years, the most important of which was the addition of extra steel plates, which added weight and reduced wheelslip.

The E82 was also the last Milwaukee electric locomotive to operate on the final day, after the Little Joes were stored upon arrival at Deer Lodge.