Wisconsin Life

I'm in Marathon County enjoying the sights and sounds at Dells of the Eau Claire Park. In order to gain a deeper understanding of the special geology found in this park, I met up with Dr. Keith Montgomery, a glacial geologist and professor of and geology and geography at UW-Marathon County.

playful music

Sometimes you have to get off the beaten path to discover a place's hidden history. The Dells of the Eau Claire provides a perfect path to the past. We're standing here in the south unit of the park. It's very quiet. We're sort of inside the bend of the river here. But the rocks here tell us of a much more violent past. The rock type here in the first instance was a lava. And a very explosive lava. The type of lava you would find in some of the more explosive earthquakes on earth such as in the northwest United States. And then, subsequently, as continents collided in this part of the world, well, 1.8 billion years ago, the continents were in very different configurations. This part of the world was in a different latitude and longitude. The continents did collide here and when they did, they ground up that rock. And so they created a type of metamorphic rock called a mylonite. And so, instead of having the minerals randomly distributed throughout the rock, as they would be in a granite, the minerals have been ground up, and you can see, they're all aligned in one direction. Just to the north, the Eau Claire River runs. The river has shaped the land as it is today. Tens of thousands of years ago the river did cut through here and what we see just over here is a bluff that one time was actually bore during the river, just as we find in the main channel today. So you can physically see remnants of that history that you referenced. - Oh yeah. You can see it in the rocks. The rocks tell us of the history. A history that many visitors are unaware of, but that doesn't stop them from enjoying the area. The Rust family has come to the park for a number of years. A lot of good memories here and I wanted to share it with my daughter. Aw... We like coming to the county park too because it's a little bit easier to get in, as well as the beauty of the Eau Claire Dells. And if you're camping, your camping site is very secluded from those around you. There are trees all around you. They have electric hook-up and there's some paved bike trails. And there's a beach just upstream, as well as the dells where the falls are. There certainly are trails for families like the Rusts to enjoy but as Dr. Montgomery reminds us, there is so much more to gain when you know the history. If you understand a little bit about geology, you can actually enlarge upon your appreciation of the environment if you can think of the processes that shaped the environment in the past. This park has a lot to offer and is worth experiencing in person.