There are lots of interesting hotels and B&Bs in Montana, but for my money the best places to stay out here are the ones you can reserve at recreation.gov. These lodgings are very different from your typical motel -- they're mostly old Forest Service cabins and fire lookouts, built decades ago for ranger patrols and now rented to adventurous travelers. Nearly all are extremely remote and quite rustic ... no electricity, running water, or paved roads at these places, just lots of solitude and spectacular views. And peace.
I've rented a number of these cabins over the years, and they've all been idyllic places. Here's one of my very favorites: the old Diamond Butte Lookout, an hour or so south of Ashland in an almost-unvisited corner of the Custer National Forest. It's a thoroughly isolated spot, and I think the lookout only gets a handful of reservations a year, but staying there is a wonderful experience. I took this photo on a July evening last year as I arrived at the lookout, just after a summer thunderstorm had passed. It was a glorious evening, watching the sun set over the prairies and hours of nighttime lightning strikes off towards the Black Hills. I didn't see another soul, and it was if I had the world to myself.