New Nevada covers much of what used to be Arizona, a small eastern-most portion of California, the southern-most tip of Nevada, the southern-most bit of Utah, and a sliver of Mexico. A few real-life locations it includes are Las Vegas, Phoenix, Lake Mead, the Grand Canyon, The Salton Sea, and a section of the Colorado River.
This region is also sometimes referred to as “The Wastelands”.
West of New Nevada is the Dark Coast. East is Arizona Deadlands.