The Ultra-trail Du Mont-Blanc is run here, a 103 mile ultra with over 30,000 feet of elevation gain. Just for kicks I checked out the UTMB entry process for 2009 here.
Qualification requires a demonstration of success in trail ultras with significant elevation gains. They have an interesting point system whereby the difficulty of your qualifying runs is estimated by adding together the distance in km and the elevation gain in meters divided by 100. For example, Bighorn 100 was 161k and 5334 meters of elevation gain: 161 + 5334/100 = 214.
Qualifying runs have to score above 65 and present a significant altitude gain and/or a sufficiently technical course. Races are worth 1 point for an estimate effort between 65 and 89, 2 points for 90-129, 3 points 130-179 and 4 points beyond that. A total of 4 points is needed to qualify, which can be accumulated with multiple runs (e.g. four 1 pointers, one 4 point run, etc. I *think*), So, looks like Bighorn 100 works as a qualifier for 2009 and 2010.
After seeing it from the plane UTMB is definitely on my 5 year wish list along with Western States, Wasatch, and Hardrock!