At 15,000'+ of elevation gain (all over the first 42 miles), Twin Peaks has more elevation gain* than any other North American 50 mile race and is arguably the toughest 50 miler in the US (or at least top 3!). This race is tough as you can find out by asking anybody who has ran it before. It is not for the squeamish. That being said, it IS a fantastic race with great support and a beautiful course. If you are looking for a fun, challenging and beautiful ultra, then Twin Peaks is for you.
Note: There is a 50K option (either via registration or dropping down during the race). If you drop to the 50K during the race or choose to run the 50K in general, you still still get credited with a 50K finish and will receive a medal and place - but no other awards.
The 50K course follows the 50M course until mile 25 then turns left to head back to the start/finish.