If there's a bright spot to the polar vortex, it's this: the frozen ice caves of Lake superior.
Since 2009, safety concerns have made the Apostle Islands off limits, but a deep freeze now clears the way. Wisconsin officials are hoping weather conditions allow the caves to remain open for another six weeks, though they admit that Old Man Winter has been especially fickle this year.
One quiet morning, Mary Dougherty and her family made the mile-walk and marveled at the stark white icicles, warm sandstone and unseen swells of water below their feet. She came back with dozens of stunning photographs of what she likens to a cathedral.
"When we recognize beauty, we recognize the sacred," she says. "That day was like a step through an amazing curtain."
The Islands are located about an hour and half east of Duluth, and hover just north of the Wisconsin shoreline. A Bayfield resident, Dougherty originally posted the pictures on her blog as a way to celebrate the day with her son before he headed back to college. But they also call attention to the risks posed by the mining of iron along the Penokee Range, she says.
Although Gov. Scott Walker disagreed, one Wisconsin legislator admitted that the mining could adversely impact the environment.