The Arizona Road Runners Desert Classic Marathon course is an out and back on the shoulder of the highway. The first 10 miles are a slight uphill grade followed by 3 miles of slight downhill to the turnaround. Then it is 3 miles of slight uphill grade followed by 10 miles of slight downhill on the return to the finish.
See what splits you need to run for hundreds of different marathons - adjusted for the specific terrain of each marathon, your goal time and pacing strategies.