At 20,320 feet (6,194 meters) in Alaska's Denali National Park and Preserve, it's the highest peak in North America. Five major ridges extend from the summit flanked by five glaciers and numerous icefalls.

Known as Denali, “The High One” in Athabaskan, the peak commands respect: not because it's a more difficult climb in comparison to the other Seven Summits, but because of extreme weather conditions that make it treacherous and unpredictable. Having almost a will of its own, Mt. McKinley's climate can lash out unexpectedly for days on end, making climbing enthusiasts turn back. In 1906, Dr. Frederick Cook claimed to be the first mountaineer to summit.

With weather extremes from –40 F to 60 F and blizzards lasting 7+ days, the climate of this peak and glacial travel conditions and altitude make this a truly challenging adventure.