Stair-step Waterfalls

Notice the “stair-step” shape of this waterfall. The gorge bedrock consists of two types of sedimentary rocks: shale and sandstone. The flakier and softer shale is more extensively eroded away by the water of Cascadilla Creek compared to more resistant and thicker sandstone. This forms the uneven shape of the waterfalls here. For over the past 15,000 years, the creek has been slowly washing away gorge bedrock, continually deepening and widening the gorge. Compare the falls in front of you to what it looked like in 1915 (image above).

In winter, ice further loosens the gorge’s rock walls through freeze-thaw action, continually widening the gorge.