According to the National Oceanic and Atmospheric Administration (NOAA) Great Lakes Environmental Research Laboratory, about 94% of Lake Superior, the world largest fresh water lake, is covered with ice, enabling thousands of people to visit the islands on foot for the first time since 2009.
It’s quite the spectacle.

Frozen Lake Superior

Woman walks dog on frozen Lake Superior by the sea caves of the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Man looks at ice formations in sea cave of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Ship frozen in at port in Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Car travels the ice road on Lake Superior between Bayfield, Wisconsin and Madeline Island. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers trek across a frozen expanse of Lake Superior to the sea caves of the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers look at a frozen rock face along the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

A woman photographs ice formations on a rock face of the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Man looks at ice formations near the sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Man slides down ice wall near the sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers look at ice formations in sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Man looks at icicle bridge near sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseer puts on crampons for ice walking at the sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers are framed by the icicles of a sea cave in the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Man looks at icicles on the bridge of a rock formation near sea caves of the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers crouch to avoid icicles in a sea cave on frozen Lake Superior at the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Icicles and hoar frost form on the ceiling of Lake Superior ice cave at the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Traffic congests at the entrance to access the sea caves of Lake Superior at the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers trek across a frozen expanse of Lake Superior to the sea caves of the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Frozen Lake Superior

A man photographs ice formations on a rock face at the Apostle Islands National Lakeshore of Lake Superior. ERIC MILLER/REUTERS

Frozen Lake Superior

Sightseers trek across a frozen expanse of Lake Superior to the sea caves of the Apostle Islands National Lakeshore. ERIC MILLER/REUTERS

Feb 17, 2014