corral canyon is fun, i believe you need a adventure pass, $5.00 a day or get the yearly one,(forgot how much). it has fire rings, picnic tables(on some camps) and a double vault toilet. i have never been bothered by the rangers, they just seem to cruise by not not pay any attention to the camp.
go here for some pictures http://bokasmo.com/pages/ohv/california/corralycn/index.html
or here
http://www.sdorc.org/ohvareas/c_canyon/c_canyon.html