We went to Big Bend in March 2007, and camped in the Rio Grande Village campgrounds. I don't remember about electrical hook ups because we were tent camping, but there are showers available at the little store adjacent to the campground. We did not make reservations for the campground, and there were plenty of available sites. Just rode in and picked out a site! Also, we saw no tarantulas, but the campground was patrolled by a friendly roadrunner.