Silurian-age rock strata at High Falls were deposited as open seafloor, tidal flat, and lowland river sediments. These 410 million-year-old layers were tilted and deformed during the Acadian orogeny, a mountain-building episode about 365 million years ago, when the strata that make up the Catskill Mountains were formed. About twelve thousand years ago, as the last glacier retreated, ice blockage diverted the northeast-flowing Rondout Creek eastward at this point. In time, the creek poured over the hard Rosendale cement rock, forming the high falls and cutting through the older strata visible on the far bank.

Photo: Steve Stoessel

Photo: Steve Stoessel

Photo: Steve Stoessel

Photo: Steve Stoessel

Photo: Steve Stoessel

Stone Ridge, New York · USA