The Dolomite Cliffs of PSP

Eagle Bluff is an incredible 150-foot dolomite cliff face. It is awesome when climbed underneath while hiking Eagle Trail and truly majestic when viewed from a boat in the bay.

Have you ever wondered why the cliffs are made from dolomite and how they were formed?

Photo courtesy of the Wisconsin Department Of Natural Resources

TL;DR

The dolomite of Eagle Bluff results from ancient marine deposits followed by unique geological processes that exposed and preserved this resistant rock, forming the distinctive bluff seen today.

3 Minute Read

Geological Formation: 

The dolomite at Eagle Bluff was formed during the late Ordovician to Silurian periods, around 450 to 400 million years ago, when a shallow sea covered the region. 

During this time, layers of limestone, which are rich in calcium carbonate, were deposited. Over millions of years, these limestone deposits were transformed into dolomite through a process called dolomitization. This occurs when magnesium-rich waters replace some of the calcium in the limestone, converting it into dolomite.

Erosion and Uplift: 

Geological forces, including tectonic activity, erosion, and glaciation, have exposed the dolomite layers at Eagle Bluff. 

Dolomite's resistance to erosion makes it more durable than other sedimentary rocks, contributing to the site's prominent cliffs and rugged landscape.

Durability: 

Dolomite is more resistant to weathering and erosion compared to pure limestone. 

This durability helps maintain Eagle Bluff's steep and dramatic cliffs, which have been shaped and preserved over time due to the rock's resistance to erosion.

Hike Eagle Trail or rent a kayak to enjoy this incredible example of ancient Dolomite cliffs!

To view Eagle Bluff by trail, visit The Camp Store at Nicolet Beach, grab a map, and then walk past the bike and boat rentals booths, along the camping road until you see the trailhead for Minnehaha Trail. That will connect with Eagle Trail and you’ll be on your way!

To view Eagle Bluff by kayak, bring your own, or rent one right on the beach. The big question is whether you choose singles or doubles!