Lots of nuclear sites, all with very wide swaths of coverage - Hanford, Savannah River, big chunk of New Mexico and surroundings, Nevada. I'm guessing places in

Lots of nuclear sites, all with very wide swaths of coverage - Hanford, Savannah River, big chunk of New Mexico and surroundings, Nevada. I'm guessing places in Colorado and the Dakotas that a little later became various bits of SAC/NORAD/etc were already homes to sensitive Air Force bases and related facilities.