The Avett Brothers, Yonder Mountain String Band, Keller Williams, Gramatik, Family Groove Company, John Brown’s Body, Pimps of Joytime and more will play the 2013 Summer Camp Music Festival. The event will take place at Three Sisters Park in Chillicothe, IL May 24-26. The news came today via the festival’s Facebook and Twitter pages as part of a controlled leak prior to the full initial artist announcement, which will come tomorrow at 5pm CST. As previously reported, Trey Anastasio Band, Lettuce, Cornmeal, Taj Mahal, GRiZ and more will also be at the festival. TAB will play two full sets, and Umphrey’s McGee and moe. will each play multiple shows at the event, as they have done in the past. Tickets to this year’s Summer Camp will go on sale Saturday, December 1 at 10am CST. You will be able to purchase them here.