Black diamond Alta, UT
Erosion Gullies drops 407 vertical feet over 1,114 feet of skiing, with a steepest pitch of 32° about 310 feet below the top. That's steeper than 70% of the 4,740 black diamond runs we've measured in North America, and the 68th steepest of 117 named runs at Alta. It faces southwest.
Facing southwest at an average 22°, Erosion Gullies gets about 125% of the winter sun that flat ground at Alta does, December through March. That's sunnier than 90% of the runs we've measured, and the sunniest named run at Alta. Its top sits at 10,440 feet.
Angled toward the low winter sun, it bakes: powder turns heavy soon after a storm, and in spring it softens early in the day and refreezes hard overnight. Shading from ridges and trees isn't counted yet.
under 25°25–35°35–45°45°+ Hover to follow the line on the map.
Measured by ZRankings from 1-meter USGS lidar. Steepest pitch is the steepest stretch of about 50 vertical feet along the skiable line. Run lines come from OpenStreetMap and can sit a little off the skied path.