Margerie Glacier and the mountains that mark it's beginning. Per the info we were told by the naturalist on our cruise, I believe that is Mount Fairweather in the background. Mount Fairweather is the highest peak in Glacier Bay National Park and marks the border between the United States and Canada. From what I understand it can only be seen on fair weather days, hence it's name. Margerie Glacier is 21 miles long and 1 mile wide. This is only a small portion of the width of the glacier, but to know those mountains are over 21 miles away is pretty amazing.