They have great facilities to camp at the fairgrounds for Untapped Music Festival (presented by Mid Valley Auto Group) that way you are right near the event all weekend. They even have free shuttles to the Friday event at Clover Island to make it easy. The Fairgrounds website describes the area-

"A facility with a western feel, full of green grass and shady trees, the Benton County Fairgrounds offers and ideal RV Rally location. With 150 water and electrical hook-ups and the ability to dry camp at least another 200 on grass, we can accommodate both large and small groups. We also have several parking lot areas that can hold countless more if hook-ups are not necessary. Our Fairgrounds has five large exhibit buildings, perfect for dining halls or vendor displays and two sewer stations conveniently located on site. Our local area boasts great weather, many golf courses, Washington’s finest wineries and the Columbia River with all of its recreational activities."

google maps

You can buy tickets for the full weekend of camping for just $54.00 by clicking the link here and then click on "BUY TICKETS".