Hi there,
Greyhound buses stop at all of Arizona"s major cities, as well as the towns along the interstate. Amtrak trains cross Arizona on two transcontinental
routes.
Amtrak can sell you a ticket to Phoenix. From there, you can take a free shuttle bus to Flagstaff or Tucson.
Another option is to take Amtrak to Williams and transfer to the Grand Canyon Railway.
Hope this helps
Vacationbuddy