Double black A-Basin, CO
4th Alley drops 667 vertical feet over 1,362 feet of skiing, with a steepest pitch of 44° about 980 feet below the top. That's steeper than 87% of the 2,251 double black runs we've measured in North America, and the 21st steepest of 161 named runs at A-Basin. It faces north.
Facing north at an average 30°, 4th Alley gets about 40% of the winter sun that flat ground at A-Basin does, December through March. That's shadier than 98% of the runs we've measured, and the 13th shadiest named run at A-Basin. Its top sits at 11,790 feet.
Shaded snow stays colder and drier, so it holds powder longer after a storm and is slower to crust over or turn to slush in spring. 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.