To start with, I must apologize for my lack of fluency regarding locomotive models/years.

While on a trip to Idaho this weekend, I observed a long line of locomotives parked in Nampa. I'd say there was at least 30 of them coupled together in a single line. Most were of SD-40 vintage. There were a few SW-1500s. While weathered, they didn't look like junk units that hadn't been run in a long time. I assumed all these units were being stored for sale, but then I noticed a few late model GE's. I don't know the model numbers but they looked like current models and with a new paint job they would've passed for new.

Question: what was the status of these locomotives? Why would late model GE's be mixed in a lineup otherwise consisting of 40 and 50-year-old units?