The RV Resort at Indian Springs Ranch in Eureka MT is a nice new campground with full hook-ups (power, water, sewer). When I was there last year there were only 30 sites completed with 65 more nearing completion. Everything was new and nice and clean. 

There are great views of the near by mountains and the park is adjacent to a wonderful 18 hole championship golf course. There is a small gift shop, miles of walking trails and an off leash dog park. The staff was very friendly.