I drive along US-12, US-89 and MT-294 from Townsend to Harlowton occasionally but I remember the first time I did and noticed a mid-sized electrical power station (abandoned) in the middle of nowhere. It is just west of the Martinsdale Colony if memory serves which is just 40 to 50 miles from Harlow but since there were only a few ranches in the area the Milwaukee Road had to build a power station in the middle of the empty quarter. That could not have been cheap.
I do not think it was a power generation plant, though I could very easily be wrong. I think it was a sub-station but it still probably cost a lot to build and maintain. I could not find the sub-station I drive by but it was similar to this photo of the Primrose sub-station.
https://historicmt.org/items/show/2216
On edit:
Ah, here it is. The Loweth Substation. 47 miles west of Harlow. The land there has a stark beauty to it. Reminds me of some of Ivan Doig's books.