Ice climbing. Mendenhall Glacier, Juneau, Alaska. After being heli-dropped north of Mendenhall Lake atop the Mendenhall Glacier in the Juneau Ice Field, Alaska, Tongass National Park, tourists enjoy a day of ice hiking high on ice wall above tent amidst the vast blue expanse of ice. 9/13/05 The Mendenhall Glacier is a large valley glacier 12 miles long. Its terminus or front foot extends into Mendenhall Lake. The Mendenhall has receded 1.75 miles since 1958. Today a vast blanket of ice covers more than 4% of the state of Alaska. The Juneau is North America's fifth largest ice field covering more than 1,500 square miles of land. It is 100 miles long and 45 miles wide. It is Alaska's birthplace of glaciers. The Mendenhall Glacier is a large valley glacier 12 miles long.