The following table ranks the 50 highest United States counties or county-equivalents by mean elevation. This list uses the "mean of extremes" elevation which is the arithmetic mean of the highest and lowest elevations.
Lake County, Colorado has the highest U.S. county mean elevation of . Lake County is the home of Mount Elbert and Mount Massive, the two highest summits of the Rocky Mountains of the United States and Canada. Lake County is also the home of the highest U.S. county low point, the Arkansas River at the Chaffee County line with an elevation of .
With the highest mountain of all North America, the Denali Borough of Alaska has both the highest U.S. county high point, the summit of Denali at elevation, and the greatest U.S. county elevation range of .
Of these 50 highest U.S. counties, 34 counties are located in Colorado, four counties in Wyoming, four counties in New Mexico, three counties in Utah, two boroughs in Alaska, and one county each in California, Idaho, and Nevada.