The settlers of Rattletail were convinced to resettle to Anza-Borrego by Chief Hanlon after they were killing wastelanders that they thought were raiders after their water. They had difficulties at first but later found a living raising bighorners.
Anza-Borrego is mentioned in Fallout: New Vegas.
Behind the scenes
Anza Borrego is most likely based on Anza-Borrego Desert State Park in northeastern San Diego County, California near Borrego Springs.