The dog, named Fred, was found by an employee Wednesday in the parking lot of the Second Chance Center for Animals in Flagstaff.
The next morning, staff members with the shelter found a microchip in Fred that let them figure out he was registered at Riverside County Animal Control.
The shelter contacted Fred's speechless owner on Friday.
The owner said Fred disappeared after she moved to Riverside in December. She didn't know how he could have ended up in Flagstaff.
Paul Fink, a veterinarian at the Flagstaff shelter and a pilot, has offered to fly the dog home to his family.