Billy, I think that if you have a Back country permit and the Park Rangers are aware that you are on an extended trip, you can leave your car at the Abrams Falls Parking area, unless that has been changed. I don't recommend it for some ugly reasons. The closest backcountry campsites in walking range for Abrams use, are Rabbit Creek, #15 and Little Bottoms,#17. They are both several miles from the Big Horseshoe, but both are near some excellent fishing. I do recommend either of these sites. You need two or three days if you are going to fish out of them. Both will take you into some pretty isolated country. You need your best skills here. Good luck on your trip.
Hugh Hartsell---East Tn.