We visited for one night as a stop between Panama City Beach and Pigeon Forge. Using the website for last minute reservations was not possible but it indicated some walk-up sites were available. There was no staff person at the entry and no way to pay for the site with money in a registration envelope. We did find a nice campground host who said we could pay at the visitor center the next day, which we did. We stayed in a pull through site with electric, water and sewer. There are smaller sites also available for tents or backing in and with fewer hookups. There is a dump station also. It was clean, peaceful and quiet. The sites are pretty close together. The gorge and visitor center were great. We did a morning hike along the upper rim and saw several of the falls and the dam before continuing our trip. If you arrive at the visitor center early you can get one of the 100 daily permits to hike to the canyon floor, but we didn't do that. There is not much around the park in terms of gas, stores or restaurants without driving 15-20 minutes. There is a playground and showers / restrooms.