Hello
Wallace creek is a popular campground especially when the weather warms up. If you're coming in on a weekend you might want to make a reservation just to be safe. During the week you should be fine. All sites are nice with concrete pads and hookups so for an overnight stop any site should be fine. There's a board at the entrance to the park showing available sites and payment instructions. You can drive through the park, choose your site and come back to pay. Cash or check only, no credit cards. If you don't make reservations there are two other parks in the area, a COE across the dam and a state park a short distance away in case Wallace is full.