Will be in Billings, Montana, for a wedding this coming weekend, then wife and I will have a rent car for four or five days before meeting up with others in Great Falls for a few days in the Glacier NP area. We are planning to head west from Billings towards Idaho and perhaps Yellowstone NP during those four or five free days. I was hoping to squeeze in a guided raft day trip during that time. What do you recommend regarding river and outfitter? Thanks.