The UP Gila Sub is the ex-Southern Pacific Sunset Route that runs 255 miles from Yuma, AZ, to Tuscon, AZ.
In the Shawmut area, the railroad works thru the Sonoran Desert and around the Maricopa Mountains. There are some pretty cool shots to be had thru here high from the mountains. Be warned it's hard work, very crappy walking, and in 100 degree weather it about killed me! Here a City Of Industry, CA, to Bedford Park, IL, Z-train hammers as they climb the 1% grade from Gila Bend to Estrella. A total of 18 miles to climb out of the Gila River bottoms and up thru these Maricopa Mountains. This is a great place to watch trains! One can see trains coming from the west over 15 miles away.