Amtrak's Southwest Chief operates daily between Los Angeles and Chicago, stopping in Needles, California (near the Arizona border), Kingman, Williams Junction (from which bus transfers are available to the scenic Grand Canyon Railway), Flagstaff, Winslow, and Gallup, New Mexico (near the Arizona border). The Sunset Limited travels three times each week between Los Angeles and New Orleans, with stops at Yuma, Maricopa (about 25 miles south of Phoenix), Tucson, and Benson. There's a connecting bus (a three-hour trip) between Flagstaff and Phoenix.
Amtrak. 800/872–7245; www.amtrak.com.