I was at Meremac Caverns this weekend. They had a two story motel there. It dawned on me that such a motel might serve as part of the Prime Base cover. In the late seventies satellite TV was becoming a going concern. I could see a motel (perhaps even a chain of motels) offering "A Dish for every room! Enjoy your own SATELLITE FEED! TWENTY CHANNELS IN EVERY ROOM!" Sure by the late eighties all this technology is totally obsolete but how many roadside motels are littered with dead technology that they just haven't bothered to remove. If not a motel than am RV park where every pad has a dish.
If the site(s) is near a microwave tower they can backdoor that feed and get into that data stream as well. In fact having a microwave tower near enough to prime base is hardly unlikely.
http://long-lines.net/places-routes/maps/MW6003.jpg
If AT&T was part of the council of tomorrow there is no reason why the towers couldn't be integrated into MorrowNet