This year its August 16th to 17th and has a great lineup:

Wilco
Brian Wilson
Medeski Martin & Wood
Kaki King
The Black Crowes
Ben Harper & The Innocent Criminals
Robert Randolph & The Family Band
Son Volt
The Avett Brothers

Camping is provided by Moose Wilson Road Campground.

http://www.festivalnetwork.com/events/details.php?ID=43