The 20 black runs in the Pyrenees whose steepest stretch is the gentlest. By the ATUDEM and AFNOR criteria, a gradient over 40% is black-run terrain; Rhodos, Rododendres at Font-Romeu Pyrénées 2000 tops out at 23% (13°) over its steepest 50 m. Official grades also weigh width, exposure and snow, so a gentle black can still be a black.
For every official black run of at least 300 m, its steepest 50 m stretch, measured with the elevation model (about 30 m precision, smoothed against false spikes). Sorted from gentlest. Very short steps may not show.
Rhodos, Rododendres, at Font-Romeu Pyrénées 2000: its steepest 50 m stretch is 23%. Next come Tubo la Glera (Formigal, 25%) and Championnat, Campionat (Font-Romeu Pyrénées 2000, 26%).
For every official black run of at least 300 m, its steepest 50 m stretch, measured with the elevation model (about 30 m precision, smoothed against false spikes). Sorted from gentlest. Very short steps may not show. Data from OpenStreetMap via OpenSkiMap.