If you're hoping to take advantage of the extended winter season to visit the Apostle Islands National Lakeshore ice caves, you certainly won't be alone.
The National Park Service rangers estimate that about 88,000 people have come to the site near Bayfield, Wis., to see the intricately formed blue and pink ice formations in and around the cliffs and sea caves. That compares with the 150,000 visitors to the lakeshore for all of 2013.
Visitor Douglas Feltman created a time-lapse video of the crowds.
The ice caves haven't been accessible for years - the last time was 2009 - and when they were, it was only for a short period of time after early February. But this year's arctic temperatures froze Lake Superior over earlier in the season, allowing a much longer period of access to the extraordinary caves.
Of the Apostle Islands, the Mainland, Sand Island and Devils Island have the most dazzling of caves, but only the ice around the Mainland caves is checked by park rangers for stability and thickness.
The National Park Service warns that ice conditions can change quickly, so visitors should monitor updates on the Apostle Islands' NPS page, Facebook page or call the "Ice Line" at (715) 779-3397, ext. 3, for closure information.