World Amazing Stuff: Ice caves in Lake Superior

Ice caves in Lake Superior

Crowds hike across frozen Lake Superior to see ice caves.

Crowds of people are flocking to northwestern Wisconsin to trek on a frozen over Lake Superior to reach dramatic ice caves accessible on foot for the first time in several years, courtesy of the long frigid winter. The ice caves on Superior's shoreline are carved out of sandstone by waves from the lake and derive their name from the icy freeze in winter that makes them glisten with hoar frost, icicles and ice formations.

Reachable in warm weather by boat, the caves are accessible in winter only by walking across ice when it is thick and stable enough. It has been five years since the ice caves were last reachable in the winter, officials said.

People have hiked over a mile across the ice in the Apostle Islands National Lakeshore since officials declared the ice a 'low risk' on 15 January 2014, according to the park spokeswoman.

According to the research laboratory, The Great Lakes in the last week reached its broadest ice coverage in 20 years at 88 percent, with Lake Superior at about 95 percent.

The round-trip trek to the caves can take three hours or more over a well-packed and slippery path with little cover to break the sometimes fierce winds. Still, the number of visitors was expected to surge over the three-day Presidents Day weekend, boosting tourist activity in such towns as Bayfield, about 18 miles west of the caves.

Ice caves in frozen Lake Superior pictures