Have not traveled this road recently but...
South of the Burro Creek Bridge (further S. than campground road) there is a road that will take you West to Signal & Alamo Roads. My old GPS called it "17 Mile Road".
Yes, Brown's crossing would really be tough on a loaded bike. Sand & a couple of short rocky climbs.
Send AZTom a pmail as I think he may travel that area some.
Mark, a Misplaced Farm Boy....