Res

Res is the name given by Joshua Graham to a location somewhere east of the Grand Canyon.

Background
Graham believes the Dead Horses to have developed their language from a combination of Res and the languages of tourists vacationing in Utah and Arizona at the time of the Great War.

Appearances
Res is only mentioned in the Fallout: New Vegas add-on Honest Hearts.

Behind the scenes

 * Several Navajo words (e.g. yá'át'ééh, meaning "Hello" in the Diné language) are spoken by some of the tribals when greeting the player character.
 * The Reservation is almost directly east of the Grand Canyon, although whether this is the same place as Res is unclear because J.E. Sawyer has deliberately been vague on the subject, even going so far as to indicate that Joshua Graham may not have the full facts correct himself.