My son and I tent camped at Spur 406 at Lake Amistad circa 2010 when the lake was high before the drought of 2011 and the low lake levels afterward. Simple campground with several sites. Great place near Highway 90 to camp. There wasn’t anyone else camping there that night. It’s on the opposite side of the lake from Del Rio and it gets very dark. There were lots of stars. We went wading in the lake at night where the old highway enters the lake and it’s easy to walk in the water or swim there farther out. The next day we caught a yellow scorpion in a jar and later released it. Good times. There was a simple bathroom. The sites have grills and maybe metal shade structures and picnic tables. There are no RV hook-ups but the road and sites might be conducive to RVs and trailers. The spur is a good 2-lane paved road but I don’t remember how big all the sites are. Per 2020 official website, camping fee was $6/night. Great place.