Boy this is tough. I just erased a page long response somehow. Oh well.
There are a lot of pull off camping spots in the Mill Creek/Cass area. One of the places we stay in in the Cass area just a mile off the road. We like it because you don't have ti go up hill. Check where Cass is on the road map. It's only a couple blocks long. Turn left at Cass, go one block west to the Stop sign, turn right and follow the road for about a mile. You will cross a low water bridge. About a qtr mile form the bridge, there will be a clearing on the right. you can stay there in the open or drive on up into the trees for a little shade. Don't be put out if there are some trucks there as the locals from Ft Smith use that place to unload. There are a lot of quad trails there. One of them is back down the raod toward Cass, cross the bridge and take the first road to the right. It goes up hill so just follow your nose. Some where up on top, there is a well used old road that vears off to the right. Take it and enjoy. It goes around and through thr Fane creek holler and come out in three different places. GET A MAP. The Ozark Forest map at the store down on the highway at mulberry creek. Ask fellow riders about places to ride. One takes out right through the trees where the camp is and goes up the hill. These are not arrowed places, but they are well used. There is a weeks worth of riding there. If you don't like that place, just go on up the road across another low water bridge. There are two or three more good rv sites on the left. There is also a good pipe spring right where the road turns to the right and heads up hill. When it's hot, we swim in the creek at the bridge. Whew. Didnt lose it this time. Mill creek is on up that road about eight miles, over to the other side. When you get to four corners, (there are really five) just go on straight through back down the other side. Like I said, get a map. Almost all of the two track roads are ridable. They do close some of them at times, but they will be well marked.