||These unusual wavy medial moraines on the Tokositna Glacier caught my eye as I flew in a small 1947 vintage bush pilot’s plane. These waves are probably caused by annual summer surges of tributary glaciers on the left. Looking north up the 20 mile-long 1,000 foot-thick glacier, the distant cloud-capped peak on the right is Mt. McKinley, also called Denali “The Great One” which, at 20,320 feet is North America’s highest mountain. In June of 2001 the glacier began surging, where a mass of ice begins to flow like a swell down the glacier and causing the front to advance.