Jason Aldean, Big & Rich, Toby Keith among Country Thunder closers

Jason Aldean, Big & Rich, Toby Keith and Blake Shelton are set to headline Wisconsin's Country Thunder Festival, which is now in its 20th year.

Big & Rich will kick off the four-day music festival, which is slated for July 19-22 in Twin Lakes, WI. Aldean will finish up the Friday night lineup, while Shelton is on board for Saturday. Keith will close out the entire festival with a Sunday evening set.

Four-day festival passes are available for the early bird price of $99 plus fees and taxes through Dec. 31 at midnight CST at the event's website. Single-day tickets will be available as the event closes in, according to the website.

The lineup also features The Farm, Wade Bowen, Steve Holy, Luke Bryan, Hunter Hayes, Neal McCoy and Brantley Gilbert. More artists will be announced in the coming weeks.

The country festival offers five camping options to festivalgoers, ranging from primitive campsites to areas with hook-ups and amenities. Camping passes are on sale now at the event's website.