Apostle Island Ice Caves Inaccessible This Winter, Likely to Become Rare as Lake Superior Warms

Feb 23, 2021

A MODIS imagery of the ice coverage on Lake Superior as of February 17, 2020.
Credit Apostle Island National Lakeshore

In 2014 and 2015 the Apostle Islands Ice Caves drew thousands of people to the icy shores of Lake Superior.

There won’t be a chance of that this year.

Despite the recent cold snap, the National Park Service says the lake ice isn’t stable enough to allow people to walk out and view the ice caves.

Apostle Islands Resource Management Chief Julie Van Stappen says we need weeks of cold to create ice that extends from Bayfield to the northshore of Lake Superior.

MODIS imagery of the ice cover on Lake Superior in 2014.
Credit Apostle Islands National Lakeshore

“The ideal conditions for good ice is cold, calm, with very little snow. So that’s that situation we had in 2014 and that really cold weather started very early. We were getting ice as early as December,” said Van Stappen.

Van Stappen says they have teams that will go out and check the quality of ice.

She says it has to be safe enough to walk out on, but also safe enough for rescue crews to get out there should something go wrong.

“If the ice isn’t good and someone goes in, the likelihood that they make it very long is very low. Even if you have a cell phone, even if you can get out, cell phone coverage is notoriously bad. It would take a very long time for anyone to come and if the ice conditions aren’t very good. They may not be able to come out,” said Van Stappen.

Opportunities to view the ice caves from frozen Lake Superior are becoming rarer.

Up until this month, Lake Superior was experiencing historically low percentages of ice.

The recent cold snap did increase lake ice coverage by more than 25%, but that still leaves majority of the lake ice free.

The last time the ice caves were open in 2014 & 2015 ice coverage was at or near 100% on Lake Superior.

Two photos taken 24 hours apart demonstrate how quickly ice conditions can change along Apostle Islands National Lakeshore.
Credit Apostle Islands National Lakeshore

“We’ve come close a couple times, but just when we think ‘oh it looks pretty good’ it’s blown out or something else has occurred,” said Van Stappen.

Van Stappen shared a graph that charts the annual maximum ice cover on Lake Superior over the years.

Between 1970 and 1995 that maximum percentage of ice cover was at 50% or below only four years, with majority of years reach at least 75% coverage.

Between 1996 and 2020, 15 years never reached more than 50% ice coverage.

Credit Apostle Islands National Lakeshore

Van Stappen says that doesn’t bode well for the future of the ice caves.

“The reality is Lake Superior is one of the fastest warming lakes in the world and the likelihood of us having caves especially that are as Lake Superior ice is accessible is getting to be a rare, rare event,” said Van Stappen.

You can view some of the ice formations from the shore on the Lakeshore Trail.

Van Stappen warned that trail can be slick and recommends caution.