Ovando’s 
Lake Upsata Guest Ranch (201 Lower Lakeside Ln., 406/793-5890 or 800/594-7687, www.upsata.com [1], $110) is a beautifully located guest ranch that offers more than the usual horseback rides and campfires, although these traditional activities are by no means neglected. The lodge and the eight guest units (each individual log cabin comes with two beds, private baths, and a stocked refrigerator) share a great view of a small private lake backed up against the Swan Mountains. Swimming, canoeing, kayaking, and fishing in Lake Upsata are each right outside your cabin door. Much of the time the ranch is booked by family and business groups; B&B-style lodgings are available for $110 per night for people who are just passing through. Summer backcountry pack trips run $265 per day; hunting and float trips are also available.
In Ovando, White Tail Ranch (406/793-5043 or 888/987-2624, www.whitetailranch.com [2], from $160 per person per day, $1,500 per person per week) offers all meals, horseback riding, and a full range of ranch activities, such as nature walks, mountain biking, and nightly campfires.
Many fishing-access sites have good campgrounds. The Johnsrud Fishing Access Site is about one mile off Highway 200, 11 miles east of Bonner.
Continuing east on the gravel road that leads to Johnsrud will bring you to several more fishing-access sites with campgrounds, including Thibodeau, Corrick’s Riverbend, and Ninemile Prairie.
Links:
[1] http://www.upsata.com
[2] http://www.whitetailranch.com