Awesome Scars of an Ice Age Waterfall
Moss Island is a narrow but long outcropping of extremely hard igneous rock called metasyenite jutting out of the waters and dividing the Mohawk River from the NYS Barge Canal. The island, which was declared a National Natural Landmark in 1976, is a veritable paradise for hikers who enjoy the rugged features, the scenic views of the waterways, the abundant berry bushes, and especially the amazing "potholes".
The potholes are actually natural chimney-like tubes in the hard rock that were carved out over several millennia by a gigantic prehistoric cataract that drained the ancient Glacial Lake Iroquois toward the end of the last ice age, when the St. Lawrence River was blocked by glaciers. In effect, the falling water carried rocks and sediment that scooped out the potholes from the bedrock ... if you were to explore the footings of modern-day Niagara Falls, you would see similar potholes forming beneath the torrential cataracts there too.
The potholes on Moss Island are quite deep, up to 40 or 50 feet, with concentric tubular walls that are nearly as smooth as glass. You may access the potholes from the northwest side of Moss Island, and descend them, carefully, much as you would a circular staircase to the beach on the Mohawk River below. Interestingly, during the Indian Wars and again during the Revolutionary War, it is said that the residents of Little Falls frequently hid their livestock in the potholes during raids by hostile forces. During the Great Depression of the 1930s, several of the potholes north of the river, which are but a stone's throw from the railyard, served as regular encampments for hobos as they traveled across New York.
You can access Moss Island and the spectacular potholes easily by automobile from Route 169, with parking in the ample lot for Lock 17. From there it is a very short walk across the lock itself to Moss Island. Alternately, you can access Moss Island from Benton's Landing in Canal Place by walking east on Seeley Street.