Speaking of Devils Tower, there are many good choices of places to spend the night nearby. Especially in the summertime, the myriad of campgrounds are popular places to overnight in a scenic locale. The former park superintendent's lodge has been transformed into a B&B, and you'll find a Best Western within 10 miles of the park. Find out more with this article on Devil's Tower lodging options.
It would be very cool to stay in a campground and see the big sky overhead. Is it Wyoming that's Big Sky Country or is that Montana?
hotels near Devils Tower you have a few choices: Best Western Devil's Tower Inn, Hulett Motel, and Devil's Tower Lodge. Then, there is camping...you could stay in one of the area's campground. The Devil's Tower KOA has cabins and RV hookups and tent sites.
Montana is Big Sky Country and Wyoming is the Equality State (or the Cowboy State), but the name could equally apply here—the wide-open spaces in northern Wyoming are beautiful. The geology of Devils Tower is really interesting too. If you don't want to stay in the park (i.e. you're not up for camping), you can also check out the town of Gillette. It's about an hour's drive away, and it's got a decent selection of hotels, so it's a good base for a day trip.