We didn't boondock in Island Park, but stayed in Red Rocks Park. It is on Red Rocks Road and we noticed as we turned off 20 onto Red Rocks Road that there were several folks who were boon docking off to the left about half way down the road to the park. DH told me as he was checking out fishing areas that he noticed a FSCG that had electricity, called Warm River. He said it was a small CG, short road into it. He said #8 was a really nice site. It was close to Three Rivers Resort or Fly Shop, couldn't exactly remember that part. Hope this helps.