Potholes are form when a rock (or many rocks) are spun around in the same spot by circular motion called eddies a whirlpool of water. The constant abrasion begins to wear away the bedrock into a hole. Once started, the feature is self-reinforcing as the hole creates an even stronger eddy and as the rocks are being spun into the hole is called a grinder and as one grinder wears away another rolls in to fill its place. Most of the work is done during periods of high flow/flood events when the velocity of the water is best able to move the grinders.
#1 What time of year were you here?
#2 At the GZ can you estimate from this location the size of each of the twin formation?
#3 Seeing many potholes along the falls what do you see that explains how they are formed? Any evidence that you can see that indicates the potholes are still forming?
#4 Optional post a picture of your adventures here so everyone can see the time of year and the spot you like best..