AT&T Sells Off 235 Cell Towers

In all seriousness, that's probably all the towers AT&T owned in those states. It's really a rarity these days to see new towers being constructed unless it's in areas that don't have good/any coverage from ANY provider. 9 times out of 10 there's an existing tower or structure in the area that a carrier could locate on and meet their coverage objectives. These situations are usually encouraged by towns as well.

I mean, think about it. GTP owns over 10,000 towers. That's quite a bit and only makes it the 3rd largest. That means there are 2 others out there with more towers, all being used by towns to "encourage" carriers to collocate instead of building their own tower.