The spiraling popularity of the ice caves brought a dizzying amount of money to the locals.

A new National Parks study found that, in 2014, the 290,060 visitors to the Apostle Islands National Lakeshore near Bayfield, Wis. spent $44 million in the area, with a $53.8 million "cumulative benefit" to the local economy.

The record number of visitors was mostly because of the 138,000 ice cave trekkers in the winter, which is normally the park's quietest season, according to a park news release.

The Bayfield Chamber of Commerce and Visitor Bureau's Executive Director David Eades estimated that the ice caves brought a $10-12 million boost and then lured some visitors back during other seasons, too.

The phenomenon of the ice caves went viral on social media in the winter of 2014, luring visitors from all over the world over the course of 8 1/2 weeks. It was the first time in five years that the caves had been accessible, with Lake Superior freezing enough to allow people to walk on it to get to the caves. It cost the National Park Service almost half a million dollars to manage the crowds

The caves opened again for a shorter season this year, bringing an estimated 37,800 visitors over the course of nine days. Those 16 and older paid a new $5 entry fee, which brought the park $140,000, enough to cover costs and make some improvements in the cave area.