Dollywood traditionally closes before dark in the summer time. From July 30 - August 12, however, you can experience the park until 10:00 PM during Dollywood Nights.
You won't want to miss rides in the dark on Wild Eagle, Thunderhead, Tennessee Tornado, Mystery Mine, and the other rides and attractions. For those on a tight budget Dollywood is offering special half-price admission tickets during Dollywood Nights from 5:00 PM - 10:00 PM.
You can find more information on dollywood.com.