I knew that UP 4878 had already passed Alta and was on its way downhill towards my favorite spot under Interstate 80.
Here, UP 4878 West -- a priority Z Train -- heads downhill on the #2 track, an EMD SD70M with 4,000 hp manufactured between 2000 and 2004, one of 1,083 such units.
In number 2 position was UP 7920, a GE C45ACCTE with 4,400 hp, followed by UP 6398 in third position, an original Southern Pacific (and the last of this order) GE C44AC with 4,390 hp manufactured in 1995 and one of 202 such units. One of a very few units still displaying actual Southern Pacific colors on the UP main.
Because I anticipated a train meet, I kept my camera rolling on the downhill train. Yes, admittedly, perhaps a bit too long.
That said, UP 6448 East emerged around the same corner and screamed past me in Run 8, as a GE C44AC, one of 120 such units with 4,390 hp manufactured in 2000.
Go here for the video on YouTube and, as per normal, click on the link, enlarge, and play with headphones for the best experience.