If you want to visit the Apostle Island ice caves, it will cost you.

More than 100,000 visitors crowded the Wisconsin shoreline last winter to see the glittering ice caves, and it cost the National Park Service almost half a million dollars to manage the crowds.

From now on, the park service plans to charge a $5 fee to visitors ages 16 and older. That is, if the weather gets cold enough to recreate last year's winter spectacle.

Last winter at least 138,000 visitors trekked across a frozen-solid Lake Superior to wonder at the caves, bristling with icicles. Their beauty inspired tourists and small children to join in singing the theme from "Frozen."

The Park Service spent $450,000 dealing with the crowds and charged only a $3 parking fee that raised just $47,000 and was bypassed by many visitors who simply parked along Hwy. 13 or in temporary lots nearby.

Last winter was the first time in five years that conditions were cold enough to make the caves accessible. Images of the icy wonderland went viral, drawing record numbers of visitors.

Last winter was the first time in five years that the weather was frigid enough to make the Apostle Island ice caves accessible.

In a news release Thursday, the park service noted that "visitation of this magnitude may be the norm, rather than the exception."

Last winter's polar vortex iced over Lake Superior and allowed visitors to make the two-mile trek out to the ice caves from January until late March.

Along the entire route there were park rangers monitoring the condition of ice and the condition of the visitors who slipped on the ice or didn't wear a warm enough coat. Some visitors simply needed directions to the banks of portable toilets the park service hauled in for the season.

The caves will open this year only if the park service determines that the ice is thick enough — eight to 12 inches — and stable enough to handle the foot traffic. Ice cave fanciers can check on conditions with the park service's ice line: 715-779-3397.

The next time conditions are right, visitors can either pay the $5-per-person day pass in the Meyers Road parking area or buy a $10 annual park pass from the Apostle Island park headquarters in Bayfield.

Jennifer Brooks • 612-673-4008