About a mile south of the South entrance to Yellowstone is Scheffield Creek(there's a sign). You can take the trail from there to an old Forest Service fire tower. About 5 miles in, but all uphill. You can spend the night in the tower (when I say tower, it's not 80 ft. in the air, but rather an elevated cabin, about 8 ft. off the ground). On a clear day you can see 60 miles or more in any direction. Take a bottle of wine and enjoy the sunset over the Tetons!!