There are spots for a 40’. If you look on google maps you can see some of the areas.

That depends. If your rear overhang is more than 4-6' you may drag going down and back up the creek crossing. I have a 30' with my rear tires about six feet back from the back end. I dragged my rear hitch even after taking the car and tow-dolly across first. On the way out I went very slow but still dragged it about three feet. No damage though. The campsites are rough with a couple that might be worthwhile going into. It is worth a walk-in, or drive your car in first, to assess it to your satisfaction. I enjoyed my three nights there.

We did it with 43' fifth wheel but stayed in one of the spots closer to entrance of area.