BAYFIELD, Wis. (AP) — The National Park Service says it’s less likely the extraordinary ice cave formations that have drawn tens of thousands of people to the Apostle Island National Lakeshore will be accessible this year.

Warmer temperatures have, so far, created unsafe ice conditions at Wisconsin’s Lake Superior shore. Minnesota Public Radio reports rangers say the wind has “unlocked” the ice at Meyers Beach, the spot where most people start their ice cave treks.

During the long, cold winter of 2014, more than 138,000 people visited the lakeshore caves and the majestic ice formations. It was the first time in five years that the caves were accessible. Last winter warmer weather delayed the opening of the caves, but when they did open some 11,000 people visited on the first weekend.

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