User blog comment:Sasquatch101/What city should it be for GTA 6/@comment-1612856-20140129111700/@comment-3301059-20140129174215

To answer your question, Blaine County is suposed to represent the high desert and forest areas of LA and San Bernardino County (i.e. Palmdale, Lancaster, Victorville, Barstow, etc). So if Venturas and Fierro wre to be added there'd just be slightly more desert region added for LV and maybe more forest region added for SF to connect to Blaine County.