Camping on Wabash Spring Road
While most people tend to set up camp right where the marker is pinned on the map above, the fact is that the Motor Vehicle Use Map for this area (see Associated Files linked below) says that dispersed camping is allowed anywhere along this road up to a distance of no more than 300 feet from the centerline of the road. Thus, you are definitely allowed to camp in places that do not appear to have been camped before.
But being close to town, you will also hear many OHV riders driving up and down this road, which you may find to be a nuisance. There are also many reports of rattlesnakes in this area, probably because this area is much closer to homes and businesses, which tends to attract mice and rats.
Otherwise Wabash Spring Road may be a great place to scout out before settling on campsites further away from town. At least, try to get here between Monday and Thursday for the best shot at finding an open site.