This was the Laramie Plains line IIRC, Started out like most, gradiose plans and a coke budget. Changed hands a time or two before being gobbled up by the UP. Lots of coal came from the end of the line SW of Walden. As traffic died off, UP sold it off. Freigh traffic did beocme rather sparse, eventually drying up to the point where the excursion traffic was all there was, and that was horribly inadequate.
The trio of FP-7A, F-7B, FP-7A were all Alaska RR power. The FP-7s ended up in Arizona with large Eagles painted on them. The B unit laguished in Laramie until she was finally scrapped. The B unit seems to me had a Rio Grande heritage, but I will need to verify that.
One of the few times I caught them, the passenger train departed Fox Park and not long after, a coal train with a pair of UP SD40-2s followed.
Robert