My trip in 2015 was (for Amtrak, at least -- I got lots of train time, LOL!) the trip from hell. Eastbound, our PDX section loco fried just out of Vancouver WA. I was waiting at WIH in the Gorge, and just kept getting texts from Amtrak putting off the arrival, till the train finally arrived 3 hours late, led by a BN loco. Hubby was at home watching it on a train tracker, and updated me when it finally started moving again. We kept that BN loco even past SPK, till the end of BN territory (I think it was MSP when they finally took it off). Here's a photo of our leaders in Montana or North Dakota:
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On the return trip, we were already quite late due to a flat wheel on a coach in North Dakota, then a blizzard in the Rockies, and then our lead loco had electrical issues alongside the Flathead River in western Montana (it was full daylight by then). We limped into Spokane, and they spent quite a while deciding what kind of unit to give us to get the PDX section going. Here's a photo of our leaders as we arrived in SPK, with (I think) the switching engines on the right:
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Here they are attaching the loco that ultimately got the Portland section going again:
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So, yes, at that time we had two Amtrak locos east of SPK, one from each section. In the case of this trip, though, they were not two RELIABLE locos.