Sure, lots of places have potholes, but how many have glacial ones?
That distinction can be claimed in Massachusetts.
A short walking distance from the Bridge of Flowers in Shelburne Falls, MA, brought us to another local sight, the Glacial Potholes at the base of Salmon Falls. This site is one of the largest collection of natural potholes in the world.
Glacial potholes, called kettles in geological terms, date back hundreds of millions of years, most recently taking the form they have today at conclusion of the last Glacial Age. As the glaciers receded, separate pools ranging from 6 inches to 39 feet in diameter were formed. The round holes were ground down by granite by a whirlpool effect of water and gyrating stones of varied sizes.
As a result of the constant whirling of the granite stones, the potholes took on a symmetrical and rounded shape. They continue to be formed today during end-of-winter snow melts when water levels rise significantly and the grinding millstones, still found in the smaller potholes, are whipped up into swirling whirlpools.
Years ago a soak in the cooling waters of the potholes was a welcome respite on a muggy New England day. But, since 2002, the pools have been “closed” to the public. Swimming is illegal and done at one's own risk. A metal fence enclosure discourages trespassers.