I always thought it odd that Milwaukee would pull the plug on their Rocky Mtn. electrification during the 1973 - 1974 Arab Oil Embargo, which drove U.S. oil prices up so much. Yes, the GE Boxcabs were worn out, however the Little Joes were only 23 years old, ( not very old as Electric Locomotives go ), and the 20 Joes could have easily handled the half - dozen trains a day then running across the division, with capacity to spare. They were also easier on the rotting trackwork, with their weight spread out over many axles.
BTW, Rob, I recall Maltby Hill as being only 2% Southbound, not 3% as stated.