Nano just told me about PTL, or La Petite Trotte à Léon, an "enlarged Tour du Mont Blanc." A new-ish race that's part of the UTMB set of races, PTL is 300 km long, 24,000 meters of vertical, must be done in 2 or 3 person teams (simultaneously, not tag-team), 136 hour cutoff, only 3 aid stations, and goes over 30+ passes/summits. Apparently it's a lot off-trail too. My friend Lint did it the last two years; he DNF'd in 2011, and hallucinated-but-finished in 2012.
I'd love to, but as with the rest of UTMB, it's the last week in August, which is a problem with many universities. I guess I just have to get a job at a school on the quarter system.
[race official site]
[participant pre-race report, with link to google earth of the course]
[participant after action report]