Originally the exit was Cottonwood. I flew in on a Wednesday into Vegas and rented a car. Arrived at Lone Pine around 3:00 PM. Went to the ranger station and got a new permit which included a Whitney exit permit that afternoon for the next day. The Ranger even listed the camp sites for me on the application. All I did was wait for him to put it in. Like I said they just cant addon to the original permit. So you need to get a new one as a walkup.