New levels of luxury are coming to Big Sky Country. The Ranch at Rock Creek (doubles from $1,600, all-inclusive), a 10-square-mile homestead, includes nine suites, a log cabin, and eight canvas-walled tents. Our favorite treatment in the spa: the Saddle Sore Soak. In May, Triple Creek Ranch (doubles from $650) will finish sprucing up 16 of its 23 cabins with pine doors and slate floors. And this summer the Resort at Paws Up (doubles from $665, all-inclusive) debuts Creekside Camp—six tents with one or two bedrooms overlooking a babbling creek.