Arizona

Arizona was a state of the United States of America. It was formerly a Spanish colony, and then briefly Mexican territory.

The Doctor, Steven Taylor and Dodo Chaplet visited Arizona in 1881. (DW: The Gunfighters)

Circa 1969, the Doctor met with the crew of a Quotron spacecraft in the Arizona desert to keep their visit to Earth secret. (TVC: U.F.O.)

In 1988, the Doctor, John and Gillian visited Arizona. (TVC: The Faithful Rocket Pack)

Circa 2009, the Doctor and Donna Noble visited Arizona. (DWBIT: Sting of the Serpent)

In 2012, the Doctor, Roz Forrester and Chris Cwej visited Arizona, where a gynoid transported Roz to New York in 1799. (NA: Christmas on a Rational Planet)

In the alternate reality of Pete's World, Arizona was still part of a United States of Mexico. (WEB: Cybus Industries website)