The Vallée Blanche, in France, is frequently recognized as the longest off-piste ski run in the world. Starting from the top of the Aiguille du Midi at 3842 meters (~12605 feet), the route descends through glacial fields and around seracs as it winds down back towards Chamonix.
If you aren’t aware, piste and off-piste skiing is more or less a European concept. Skiing on piste means skiing on marked, often groomed runs graded by difficulty. Off-piste refers to anything that’s off these marked trails and is usually considered backcountry. While open terrain on resorts in the United States will almost always be controlled for both avalanches and safe conditions, skiing in Europe is a lot more free and open, allowing you to head beyond the pistes at your own desire.
The Vallée Blanche route is for experts only and should always be done with a guide.