Published: Jan 01, 2021
Last Updated: Nov 30, 2023
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. (You can find our Mendenhall Glacier Ice Adventure tour here.)
Check out this digital adventure to see what it’s like to step foot inside the ice caves under the Mendenhall Glacier. Listen to the sounds of the stream running through the ice as you explore the 360 degree view around you.
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.
Where are the Ice Caves?
There are not many places in the world which allow you to experience every stage of the water cycle at once. The Mendenhall Glacier happens to be one of these unique locations, which makes your experience in an ice cave even more magical!
The Mendenhall Glacier is located in the Mendenhall Valley, and stretches over a whopping 12 miles! You can find the Mendenhall Glacier just 12 miles from Downtown Juneau. The otherworldly ice caves, located inside of this glacier, are only accessible to those willing to canoe or kayak to the edge of the ice and make the trek along the glacier. The journey takes half a day and is only recommended for those with an experienced guide familiar with the water and terrain.
How do you find an ice cave?
Glaciers and especially the ice caves underneath, are constantly shifting, melting, and collapsing which causes them to be everchanging and tricky to find. Typically, a trickling stream coming from the glacier can lead to an ice cave opening. Once you locate a cave, it is physically possible, but not always safe to immerse yourself inside the frozen landscape while water rushes through the surrounding crevasses. It is never advisable to enter an ice cave without a guide or the proper equipment.
This 360 view shown above is from one of the many different ice caves within the Mendenhall Glacier. While ice caves are beautiful natural formations, there are so many other features on the glacier to be discovered other than the ice caves. The ice can be accessed by a very technical trail system, or by paddling across the lake, but we do not recommend attempting this journey on your own as many adventurers lose their way on unmarked trails or do not know how to navigate icy waters. We highly recommend hiring a guide service to bring you to the glacier. One of which is the Juneau Mendenhall Glacier Ice Adventure Tour, where you will explore the sapphire ice above or below the glacier. This tour does a great job of safely finding the best features of the glacier on any given day, but everyone should know that caves can never be guaranteed and should never be expected
How is an Ice Cave Formed?
Ice caves that are accessible at the Mendenhall Glacier are most commonly bedrock caves surrounded by ice, but the fact that they’re temporary makes them a little bit different than just any bedrock cave. Since the ice melts and shapes differently and glaciers constantly advance or recede, ice caves are never around for long. For that reason, only a lucky few will have the opportunity to explore an ice cave before they disappear and each experience is unique!
The formation of an ice cave starts when water flows through a glacier and melts out a passageway in the ice. The warmer temperature of the water creates a cavity that expands into a cave formation. The opening to this passageway is called a moulin. These small to large holes in the surface of the glacier can run long distances through the ice, sometimes all the way to the glacier's terminus (face, or end of the glacier) which can sometimes be the ocean itself depending on the location of the glacier. If you have the chance to see a moulin on the glacier, watch your step! These glacier features can be hundreds of feet deep.
Although some ice caves are formed by flowing water, some ice caves in other parts of the world have formed from hot air and water associated with geothermal activity in that area.
Where in the world are the best ice caves?
The ice caves found in the Mendenhall Glacier are some of the most famous in the world! The complexity and ever changing intricacies of the Mendenhall Glacier ice caves attracts explorers year after year. That being said, you can find ice caves in many other locations where there are glaciers including Iceland and Patagonia.
Crystal Cave, perhaps the most famous ice cave in Iceland, is renowned for its intensely blue ice. It is located in an outlet glacier from \Vatnajökull.
Norway is another place that travelers might expect to find ice caves. The Nigardsbreen ice cave is so beautiful, one scientist referred to it as an ‘Ice Cathedral’.
It might surprise you to discover that there are ice caves to be explored right in the lower 48! Some of the most well known are located in Granite Falls, Washington. The Big Four Ice Caves can be found in the Big Four Mountain, a mountain belonging to the Cascade Range.