Mendenhall Glacier is a glacier about 13.6 miles long located in Mendenhall Valley, it is about 12 miles from downtown Juneau in the southeast area of the U.S. state of Alaska. The glacier and surrounding landscape is protected as the 5,815-acre Mendenhall Glacier Recreation Area, a federally designated unit of the Tongass National Forest.
The Juneau Icefield Research Program has monitored the outlet glaciers of the Juneau Icefield since 1942, including Mendenhall Glacier. The glacier has also retreated 1.75 miles (2.82 km) since 1958, when Mendenhall Lake was created, and over 2.5 miles (4.0 km) since 1500. The end of the glacier currently has a negative glacier mass balance and will continue to retreat in the foreseeable future.
It was originally known as Sitaantaago ("the Glacier Behind the Town") or Aak'wtaaksit ("the Glacier Behind the Little Lake"), also latinized as Aakwtaaksit, by the Tlingit. The glacier was named Auke (Auk) Glacier by naturalist John Muir for the Tlingit Auk Kwaan (or Aak'w Kwaan) band in 1888. In 1891 it was renamed in honor of Thomas Corwin Mendenhall. It extends from the Juneau Icefield, its source, to Mendenhall Lake and ultimately the Mendenhall River.
Few visitors, however, see the glacier from its most spectacular vantage point: inside it. Deep within the glacier, there’s a magical blue world of ice caves unlike anything you’ve seen anywhere else in the world.
Climate change
The US Forest Service, which manages the Mendenhall Glacier, says "because glaciers are a product of climate, they respond to climate change." The Mendenhall glacier has been in retreat since the end of the Little Ice Age in the 1700s. In a joint article for the Juneau Empire Geologist Cathy Connor and Geophysicist Roman Motyka, both professors of the University of Alaska said "climatic warming coupled with ice loss through iceberg calving are the reasons the Mendenhall Glacier is retreating and shrinking."
