The communities listed are places that have towers. (Is that correct) In the analog days we got service from both the Minnedosa and Rivers Towers. Nothing that you could depend on. Will this LTE possible make the service in Rapid City any better.
Sorry for the delay - I went through this with our Engineering team and honestly the indoor LTE coverage in Rapid City is going to be "hit and miss" depending on your location.
There are some terrain challenges that make it difficult to reach Rapid City optimally. At this point the best suggestion I can give is wait and see how it is and perhaps a well placed booster (would have to have some height to it) would assist in improving indoor coverage.