Nevada

In the early 21st century, when the United States was divided into thirteen commonwealths, the old state of Nevada became part of the Southwest Commonwealth, along with Southern California and Hawaii.

New Reno, Broken Hills, Vault City and Gecko, a quite diverse collection of towns, are all in what was known as Nevada.

Desert Rangers are also a faction living in the Nevada area. They are desceded from people who survived the devastation when Great War happened, likely living among the badlands of Nevada. This small community kept a strong survivalist contingent -- so they still had some small arms and books. They probably had something like the cliff-dwelling Indians going on for their town. Tycho was one of the Desert Rangers.

According to Tycho's father, in Las Vegas lived the same fat mobster as Gizmo in Junktown was like. This is referrence to Fat Freddy, the Wasteland character. Las Vegas localisation is beyond eastern edge of the Fallout worldmap (and beyond western edge of van Buren worldmap).

Hoover Dam lies on the border between Nevada and Arizona. The NCR supply train sometimes arrived to Hoover Dam from the west.

Appearances in games
Fallout 2 takes place partly in Nevada, as would Van Buren if it were finished. Nevada was mentioned by Tycho in the original Fallout.