Airports and USAF bases would make for some pretty cool locations to explore and loot.
Airports would be a good place to find lots of clothing and random items in the baggage, fuel, and some small amounts of food. There would also be plenty of vehicles and spare parts, as well whatever materials you might salvage from the parked planes. Lots of zombies, on par with a mall.
USAF bases would be lucrative to loot but very dangerous; similar to the National Guard Base, with still active automated defenses and mines. There would be some small arms and ammo of course, along with maintenance equipment and fuel, but the real prize would be the military aircraft and their armaments. You could take the weapons off of some of them and use them on your vehicles, such as the GAU-8 Avenger Gatling Cannon from an A-10 Warthog ground attack aircraft. Hydra-70 rocket pods from Apache helicopters might also be mounted on your vehicle. More sophisticated or large weapons like guided missiles or bombs might be dismantled for electronics and explosive materials. If you are lucky, you might even find a nuclear bomb, which while unuseable https://en.wikipedia.org/wiki/Permissive_Action_Link), could be disassembled to yield explosive material, plutonium, and electronics.
https://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunderbolt_II#Weapons
https://en.wikipedia.org/wiki/GAU-8_Avenger
https://en.wikipedia.org/wiki/Boeing_AH-64_Apache
https://en.wikipedia.org/wiki/Hydra_70
I don’t know about you, but I would LOVE to put one of these on my deathmobile.