Natural Rock Arch, Boulders & Potholes at Lion's Head

by Douglas Cox

The Niagara Escarpment, Bruce Peninsula, Ontario

The 'Eagle's Nest' is a cluster of potholes containing some large rounded boulders, located in the cliffs of the Niagara Escarpment overlooking Isthmus Bay near the town of Lion's Head. This is the view looking west along the Escarpment towards the town of Lion's Head and the harbor. From the lake, the boulders high up on the cliffs appear like the eggs of a huge eagle.
View of Isthmus Bay

Potholes at the Eagle's Nest

The photo at right shows potholes separated by a rock arch, and rounded boulders and gravel that fills one of the potholes. This photo was taken in August 2004. Scroll the image downwards to view the scree at the base of the cliff.

The upper part of the photo shows the gravel and boulders which fill the pothole located on the far side of the rock arch. The gravel is easily eroded, and gravel and boulders occasionally tumble down the cliff.

Below the arch, some of the boulders that fill the hidden pothole are visible, and the ones at the bottom seem to be perched in a very precarious position.
The Eagle's Nest

Rock Arch Exposed by Recent Erosion

A large hole recently appeared to the right of the rock arch. The  potholes on either side of the arch are connected below. The boulders in the foreground appear ready to tumble down through the hole and down the cliff, and their fall could initiate a possibly damaging rockfall. The rock arch or bridge could be destroyed by the impact of large boulders crashing down on it from above, which may become undermined as rocks below fall away. The diameter of the pothole on the left is about 15 feet.
The rock arch from above

Linked Potholes

Several potholes that are linked together produce the unique features of Eagle's Nest. The small diameter partial pothole on the right opens into a larger hole. A boulder under a patch of grass marks its bottom.

Rounded boulders are perched on the rock arch which forms part of the wall of the filled pothole to the left of the arch. More boulders are piled one upon another in both potholes below the arch.
Partial potholes and rock bridge

Copyright © 2004 by Douglas E. Cox
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