A Tucson to West Colton manifest train makes good time passing by the siding at Shawmut, AZ.

One of what seems like an infinite number of cacti looks on as a pair of UP engines climb up the hill out of Gila Bend with a rack train.

Another Eastbound crests Shawmut Summit.

An Eastbound crests Shawmut Summit.

An Eastbound approaches Shawmut Summit.

Eastbound stacks on the Sunset Route blast up the hill through the Sonoran Desert National Monument near Shawmut, AZ, as the sunset begins.

Three SD70Ms lead a westbound manifest through the Sonoran Desert National Monument.

A westbound stack train passes through Shawmut and the Sonoran Desert National Monument. The Maricopa Mountains are in the background.

Late on a winter afternoon, an eastbound UP stack train blasts up the 1.0 percent at Shawmut as shadows engulf the slopes of the Maricopa Mountains.

A very long stack train makes its way up the one percent grade to Shawmut through the heart of the Sonoran Desert.

Ex-SP tunnel motor 4464 leads an eastbound up the inclined right-of-way surrounded by blooming ocotillos at Shawmut.

Seven units, no waiting...

The silence of a desert sunrise is broken as UP 9774 slowly grinds uphill with brand new autos in tow.

Eastbound intermodel with 2 new ES44ACs trailing

An eastbound intermodal train snakes through the curves at Shawmut as it fights the 1.0 percent grade to the summit at Estrella.