The ice caves on Lake Superior near the Apostle Islands will soon close for the season.
In a news release, Apostle Islands National Lakeshore Superintendent Bob Krumenaker says access will close by Sunday night. He says the ice is weakening and they can see the edge of the ice coming closer to shore every day.
He says the formations are also melting and some have already fallen, raising concerns.
More than 124,000 people have visited from Jan. 15 through Sunday.
The last time the ice was thick enough for people to walk on to see the caves was in 2009, but only about 8,400 visited in January and February.
Krumenaker says if ice conditions deteriorate before then, the access could close sooner.