Double black Crested Butte, CO
Moosehead drops 318 vertical feet over feet of skiing, with a steepest pitch of 52°. That's steeper than 100% of the 2,251 double black runs we've measured in North America, and the 1st steepest of 227 named runs at Crested Butte. It faces north.
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.