I have been running some routes in Summit County (Colo.) as time trials for many years. One good one is from the Ptarmigan Trailhead in Silverthorne to the summit of Ptarmigan Peak. Start = 9100 ft.; summit = 12550 ft. Total climb is 3640 ft. My best time (and the FKT to me) is 81:25 on 8/30/98, but perhaps this post will inspire someone to do it faster. I should say that one wants to use the alternate trail, what many call the "jeep road" since that is a mile shorter than the normal trail used by everyone. Go right at the power line at about 0.8 miles.
(founding editor, Ultrarunning magazine)