FAULT ICE CAVES
- NEW YORK -
The largest known open fault in the United States is basically a giant natural refrigerator.
Located high on the Shawangunk Ridge, the Ellenville Fault Ice Caves are the region’s natural air conditioner. Even in the dog days of summer, the ice caves at Sam’s Point are home to a thick layer of ice.
The ice caves are located within the Ellenville Fault, which is the largest known exposed fault system in the United States. The faults create deep crevices and small caverns, which are sheltered from the sun and outside environment, allowing temperatures to remain near or below freezing much of the year. This allows for ice to remain late in the summer and often until the next winter.
Interestingly, the caves act as a sort of natural refrigeration system for the surrounding area. While the top of the Shawangunk Ridge is only about 2,200 feet above sea level, the microclimate created by the ice caves has allowed plants that normally reside farther north and at much higher elevations to exist nearby. As such, there are large stands of northern and alpine plants such as black spruce and mountain ash.
In 1967, the ice caves were designated a national natural landmark by the National Parks Service, due to their unique geology and importance to the regional ecosystem. In the 1990s, the caves and nearby ridgetop were purchased by a non-profit, eventually becoming part of Minnewaska State Park in 2015. Since the 1990s, the caves have been restored to their natural appearance, with only ladders, railings, and solar-powered lights existing to ensure visitor safety.