Mendenhall Glacier (also Sitaantaagu or Áakʼw Tʼáak Sítʼ) is a glacier about 13.6 miles (21.9 km) long located in Mendenhall Valley, about 12 miles (19 km) from downtown Juneau in the southeast area of the U.S. state of Alaska. The glacier and surrounding landscape is protected as part of the 5,815 acres (2,353 ha) Mendenhall Glacier Recreation Area, a federally designated unit of the Tongass National Forest.

The glacier originally had two names: Sitaantaagu (“Glacier Behind the Town”) and Aak’wtaaksit (“Glacier Behind the Little Lake”). Inside the glacier are the stunning blue ice caves, accessible only to those willing to kayak to the edge of the ice and then climb over the glacier.

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 1929, when Mendenhall Lake was created, and over 2.5 miles (4.0 km) since 1500.

The Ice Caves located at the Mendenhall Glacier in Juneau, Alaska are natural ice formations tucked away in one of the most beautiful places on Earth. The caves come and go as mother nature chooses and are accessible only to the most adventurous of travelers. When you step inside, you will immediately notice the glacial ice surrounding you is cerulean blue. The ice appears this color because it absorbs all colors of the visible light spectrum except blue, which it reflects. Thousands of years of packed snowfall creates an enormous amount of weight and compresses air bubbles out to form the ice. The density of glacial ice and transmission of blue wavelengths is what allows this vibrant color and makes it different from other ice formations closer to the surface.

Sadly, this Juneau glacier is retreating increasingly fast as climate change warms the ocean. The Mendenhall Glacier has receded almost two miles since 1958, while previously it had receded only 0.5 miles since 1500. The ice caves are in part a function of this glacial melting. Images of the caves circulate the internet with such captions as “otherworldly” and “surreal,” but “shrinking” and “fleeting” could be used as well, as this glacier creates incredible ever-changing landscapes while we watch it melt away

According to atlasobscura.com; en.wikipedia.org; alaskashoreexcursions.com. Source of photo: internet