Growing up in the LA, area if you are into trains, then you remember the black locomotives with a red front and a big white SP written across front. Southern Pacific own most of the rail road tracks in Southern California, and I have many memories of them. I remember that they would send two EMD SW 1000X to Hawthorn CA, to pick up freight. I believe some of this freight, was part from Northrop Grumman to build Boeing 747s.
I remember when my family and I, went camping in Solardad Canyon north of LA, and a SP track was near us. SP would operate a train believe twice a day, and locomotive ( very likely EMD SD45s) would run pretty high notch, and because the trains were so long, they would have another group of locomotives in the middle of it.
Sadly, SP was bought out by UP in the mid 90's, so when I visit LA, I may see some parts of SP left, but the rest is UP, so I miss the old Southern Pacific Rail Road.