The population of Miles City has been almost constant for 100 years. Up a thousand, down a thousand, but basically right around 9,000 since 1917. That is more than a bit odd but, hey! that's us.
Because of that, you see very, very little spec construction and the rental market is TIGHT. Last time it was easy to find a rental, Reagan was president and the Milwaukee went bankrupt.
Because this is also not a high income neighborhood, rentals aren't all that worthwhile. It's why so many rental projects are aimed at low income. That's where the money is, in subsidized housing.
If you think it's bad here, try Bozeman. If you aren't a millionaire, you aren't living there.