Of the trail runs I do regularly, the Cottonwood – New Army Pass loop is the closest one to Los Angeles that goes over 12,000′. It starts at an elevation of about 10,000′, and reaches an elevation of 12,300′ at New Army Pass.
The run loops through glacier-sculpted Eastern Sierra terrain, crosses the crest twice, and along the way passes some spectacular high mountain meadows, lakes, and stands of weather-hardened foxtail pines.
Because of the altitude and the technical nature of some sections of trail, this run feels longer than the 21.25 miles indicated by my GPS. Another reason it seems longer is that I usually do the run as a day trip, driving from a few hundred feet above sea level in the San Fernando Valley, up to the Horseshoe Meadow trailhead at 10,000′. Depending on the number of photo stops, and if I have to stop for water, the loop can take 30% to 40% longer than a loop of the same length and elevation gain near sea level.
Today’s run of the loop was outstanding. Short-sleeve and running shorts weather, and people on the trail as happy to be there as I was.