I’ve always been more worried about mobs of hungry moochers than the govt. Fact is, the US govt only has enough forces to hold a few medium sized population centers. Us here in flyover country are going to be on our own.
Should be pretty easy to close I-15 at the Utah/Arizona border and keep the hordes from L.A. out. I-80 from Cal is more open but there’s not much cover so it could be interdicted without a lot of trouble. There are plenty of places with high ground and good fields of fire along I-80 in Nevada.
Please do not spread that around. I want my bunkers to stay safe. Do not forget about Hwy 89 in your plans.
First thing I ever did as a "survivalist" (what is now called a "prepper", or what used to be called an "American"), was to identify all the bridges between population centers and me.
Nourish the inner sapper.