I know you need a parking pass at the TH, it's 5 bucks per car, which you can get at the TH. I was there about a week ago. I even saw a rep of the Sky Lakes Wilderness taking surveys of hikers. I did a survey, she didn't ask about a forest pass.
Philoparts was there too, he didn't mention needing a forest pass.
A pass wasn't mentioned on this link either:
http://www.outdoorstore.com/activities/ ... ughlin.phpPretty sure its just a 5 buck parking pass.
General info: A lot of people start at 8-9, I found. I started at 6.30 with a buddy of mine and we were the 6th auto. We passed probably 40 people on our way down (all going up, I was 1st that day TTT). I made a quick summit by 9am, was pretty proud of myself, to be honest. Last: DO NOT take NF3650 to the TH, it is apparently a crap road. Take NF3661 that is about 3 miles farther east on Hwy 140. It's a little washboarded, but cake.