It Lies where it Falls
As 1979 drew to a close and 1980 loomed, different parties were negotiating and debating the future of the transcontinental line across the west. It had long lived under the "understanding" of being a money pit, losing dollars to the corporation at large, and worth more dead than alive. The ICC would later uncover accounting practices that double-counted maintenance expense across Lines West, and that contrary to the narrative, the mainline to the West Coast was one of the few pieces of the Milwaukee Empire that added positive cash to the beleaguered carrier.
In 1980 the state of Montana was desperately trying to secure funding to save the mileage from Miles City west. The prospectus report authored in the early part of that year offered this look at the future operation and fate of the line, with a cost to the State of Montana of $55M payable to the Trustee:
"On February 29, 1980 the reorganization court ruled to allow an immediate embargo on Montana lines west of Missoula, MT. Service on Lines east continue with FRA funding through March 23, 1980. What is likely to happen in the near future? It appears quite likely that the reorganization court will reach a finding as to which reorganization plan (if any) will be implemented*. Service west of Miles City will be discontinued about March 23, 1980, unless arrangements are made with the Trustee to cover the net cost of such service. However, congressional action to provide service for 30-90 days is being sought by the Montana congressional delegation and the outcome of said action is unknown at this time. Should Montana be successful (1) in raising necessary venture capital, (2) securing the requested loans and grants from the Federal government, and (3) concluding negotiations with the Trustee then it will be possible to establish successor rail operation soon after funding runs out." 
*It is always possible that the reorganization could direct the liquidation of the estate
As this quiet solitude of the mainline's rise into the Rockies bears witness - these efforts were in the end, unsuccessful. The Trustee had set March 1 as the date for Montana to secure funds and the State could not commit by that time. It was another setback in a series that had seen the Trustee raise rates that discouraged business, pull modern SD40-2 diesels back to the Midwest leaving Western trains underpowered and unreliable , and all in the face of accounting that provided the false case for termination.
Today the Milwaukee's mainline rests where it fell, a legacy of questions and potential behind it as footnotes to the history.
1) Montana Department of Agriculture. "Prospectus for Providing Continuing Rail Service on Milwaukee Lines Located Between Miles City, MT and Marengo, WA." March 7, 1980 http://milwaukeeroadarchives.com/Bankruptcy/MontanaStateRailCorpPlan030780.pdf
2) Sol, M. "The Milwaukee Road's Demise, Notes from Michael Sol." https://www.american-rails.com/support-files/milwaukee_road_demise.pdf