I stayed here with my family in mid-August 2011 and it was a pleasant stay.
The room was nice. It was relatively spacious, had lots of books for browsing, and comfortable beds. Additionally, there was a large private deck with nice views through the trees of the valleys in Wilson. Soft robes were included and the wood smelled great throughout the house. However, the shades were basically sheer so in the morning the light would shine right into the room. This in combination with the kitchen being directly above our room made it difficult to sleep past 7:30 or so, which I guess wasn't too bad since breakfast was at 8 each morning. Also, there were very few places to store clothes in the room.
The breakfasts were good. They are heart-healthy, and Sally and Denny, the hosts, painstakingly create healthy fruit and granola creations and homemade juices. There are also cereals for kids if you want them. The conversation with other guests, as everyone sits around the table, is interesting. Since you sit at a big table with everyone staying, you certainly learn about other people from all over. Breakfast is also a good time to get in-the-know advice from Sally and Denny about hiking trails, white water rafting, or anything else you need to know. They are extremely knowledgeable and will gladly help you with whatever you want to know.
The location is great. It is in Wilson, a quiet town with a few shops 10 minutes from Jackson proper. It's up a quiet, windy road, which makes it silent at night which is wonderful.
Overall, Sally and Denny were very accommodating, helpful and welcoming. It's not for everyone (there are 95 steps from where you park to the treehouse where you'll be staying), but if you want a unique, homey experience, consider A Teton Treehouse.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC