BAYFIELD, Wis. – Stalactites point downward like frozen daggers, water molecules morphed into icicles taller than two-story houses.
It happens every year along the shores of Lake Superior near Bayfield, but few have seen the spectacular ice caves in the Apostle Islands National Lakeshore in many years.
For the first time since 2009, ice along the shore is solid enough to support hardy visitors willing to hike more than two miles round-trip to ogle the natural sculptures. When word recently filtered out that the caves were open, thousands trekked out to see them.
Numerous indentations in the billion-year-old Cambrian Era sandstone have created caves where kayakers sometimes paddle in during the summer. They’re not large caves. The National Park Service and the caving community define a cave as anything that’s at least 50 feet deep.
Water from several streams that flow along the bluffs as well as surface and groundwater have created exquisitely beautiful ice sculptures. Icicles are formed from waves blown against the rocks while temperatures are below freezing. Meanwhile, delicate crystal-like formations are birthed by humidity colliding with cold air.
“One of the interesting things is as long as it remains this cold, there will be growth of those kind of features. Once we get some melting, the formations melt a little bit and re-form,” said Bob Krumenaker, Apostle Islands National Lakeshore superintendent. “They’re still spectacular but not as delicate.”
Walking out to the caves can be arduous depending on weather and conditions of the shoreline, which can range from uneven ice to hip-deep snow.
“It’s not uncommon to be out there and hear the ice crack. It’s almost like it’s a living organism,” Krumenaker said. “It’s complicated and fascinating.”
Conditions can change quickly. Last February, park staff planned to open the caves to visitors and were meeting one last time when the phone rang in Krumenaker’s office.
It was a staff member who had just checked a wave camera and noticed the ice had broken up overnight. Plans to open the caves were called off.