shawn 7. it is both. its got sand and the big heay equipment has been digging it out for many, many years.it is getting smaller cause the car lot people have been buying the land to make car lots out of it. there are walls out there that only someone crazy will climb, once you hit the top you get air. theres another place over buy the river that has some sand hills, but its not quite as big.as far as the big dunes there are no posted signs, but the police dont mess with anyone, they just ride on by. the land owners is oxford construction, they put the signs for there protection if some one gets hurt.i will try to take some pictures with my mothers camera and post them.its not a huge place, but i guess that depends where your used to riding.