Zac Brown Band is the fourth act announced to join the 'Road to the Ram Jam' series and sweepstakes. Kellie Pickler, Brantley Gilbert and Easton Corbin have all signed on for the invitation-only 2012 Ram Jam concert, which takes place in Nashville later this year. In addition, all four artists receive a year lease on a 2012 Ram 1500 Laramie Longhorn truck, which will be auctioned off in early 2013.

The proceeds from the ZBB truck will go to the frontman's Camp Southern Ground for children with development disabilities. "We'll have an organic farm there, straight farm-to-table," the singer tells The Boot of the camp, located just south of Atlanta. "The kids will be able to eat what they pull up from out the ground that day. It's a big project, a big undertaking."

Ram is also helping out the camp by donating trucks for the staff to use. "To me, there's nothing more important than helping kids," says Zac, "and it's great to know that with support from our friends and fans, this camp is going to make a huge difference in the lives of each and every camper."

ZBB is also giving fans a chance to win a digital download of the band's new single, "The Wind," which appears on their upcoming album, Uncaged, out July 10. Also up for grabs are collectible posters and vinyl records, as well as a trip for two to the concert on Dec. 29 in Nashville.

Road to the Ram Jam's fifth and final concert performer and sweepstakes participant will be announced in August.

Get more information on the sweepstakes here.

Watch Zac Talk About Ram Jam

Watch Zac Brown Band Live in Our Studio