Where is the largest known area of alpine permafrost located?

The largest known area of alpine permafrost is located in western China, covering approximately 1,500,000 square kilometers (580,000 square miles).1

While permafrost is most widespread in Arctic and subarctic regions, alpine permafrost occurs at lower latitudes in areas of high elevation where temperatures of 0 °C or colder persist for two or more years. In contrast, alpine permafrost in the contiguous United States is significantly more limited, spanning about 100,000 square kilometers (about 38,600 square miles) within the high mountains of the west.1