For nearly fifty years, Lake George was famous as the largest glacier-dammed lake in North America with a unique natural phenomenon. Each winter, Knik Glacier would advance and block the outlet connecting Lake George to the Knik River. As the colder months continued, the lake filled with glacial meltwater and calving ice, creating intense pressure behind the ice dam. When summer arrived, this pressure would finally cause the dam to rupture, releasing a dramatic torrent as Lake George swiftly emptied into the Knik River. This annual event was so significant that Lake George was designated a National Natural Landmark in 1967.
This phenomenon, unfortunately, has not occurred since 1967 due to the receding Knik Glacier, likely impacted by climate change. Without the glacier’s advance each winter, Lake George can no longer self-dump, marking an end to this natural spectacle. Today, this historical event remains a part of Alaska’s unique glacial heritage, and visitors can still marvel at the lake and surrounding area during our tour options in the region.
The video provided above features excerpts from AAF-10633, sourced from the Stewart’s Photo Shop collection. For further details, please visit the Alaska Film Archives directly.