Actually, those RS-1s are really EX-Spokane International. There was a VERY interesting article about this road in the Summer 2016 issues of Classic Trains.The SI dieselized with nine RS-1s in 1949. The UP bought the SI in 1956, by then the SI was basically a connecting road between UP and the CPR. Union Pacific leased rebuilt F9s to the SI and simultaneously leased out the SIs own RS-1s or used them on UP locals. The RS-1s were repainted into UP Armour Yellow but lettered for the SI because it was still a wholly owned subsidiary until late 1969. I like the original SI scheme better TBH.
-Ben