My wife and I and 8 kids (ages 18 - 6) are going to spend a week in Big Sky at the end of July and are looking for things to do for fun. We like hiking, biking, rafting, climbing, swimming. Is there a less expensive alternative to rafting other than the Geyser Whitewater Expeditions? We also will have a few extra days to spend in early August and are trying to decide where to go. Any suggestions, i.e., Grand Teton, Glacier NP, Whitefish?