A favorite spot in Iowa for geologists and rock hounds alike, the Devonian Fossil Gorge is a window into Central Iowa’s geologic past. First exposed by the floods of 1993 and 2008, this area of fossilized sea bed dates back 375 million years.
Stepping on land that is over 375 million years old is an amazing life experience! Read on to learn more.
It’s a Natural Wonder
Imagine walking on a 375 million-year-old sea floor and discovering fossils of prehistoric marine life. It’s a rare experience that can be enjoyed at Devonian Fossil Gorge near Coralville Lake. The site was uncovered in 1993 when flood waters overtopped the emergency spillway of the dam, washing away sand and debris and exposing limestone bedrock. It was re-exposed again in 2008 by another flood of the Iowa River.
It’s a great place to walk around, but you’ll need sturdy shoes as the surface of the limestone can be uneven. Signage explains the fossil formations and the history of the area. You can see well-preserved fossils, including horn corals that look like bones and brachiopods (which resemble little cheerios). The fossils are very easy to spot, but please don’t touch or remove them, which is against the law. It’s also a good place to look for faults and folds in the rock that tell a story of the Earth’s geological history.
It’s a Family Favorite
When the water flooded the area in 1993 and 2008, it wore away huge trees, soil, and portions of the road that eventually exposed the Devonian Fossil Gorge. This archaeological wonder allows visitors to explore fossils that date back 375 million years.
This site is a great spot for kids to explore. Bring blank white paper and crayons to make rubbings of the fossils you find. My kids had a blast doing this and it allowed them to see the rock up close and learn about fossils in a hands-on way.
The Corps of Engineers is getting an update to its website which will feature a new app that will help you identify the different types of fossils that are found at this site and more about how these fossils came to be there. I recommend visiting during the spring or fall, or on a sunny summer morning before things get too warm. A must-see place!
It’s a Great Place to Explore
Unlike most bedrock exposures in Iowa, which occur on cliff faces, the Devonian Fossil Gorge is found in the spillway of Coralville Lake. It was exposed during the floods of 1993 and 2008 when waters flooded over the dam’s emergency spillway and cut deeply into the bedrock.
This created a canyon that exposed layers of sedimentary rock and limestone, including fossils dating back 375 million years. It’s an archaeological wonder, one that geologists call a “fossil gorge.”
I visited the gorge with a group of kids and adults. They were fascinated by this rocky wonder. It’s a great place for people of all ages to explore, and it’s a wonderful way to see what life was like on Earth millions of years ago.
It’s a Great Place to Learn
It’s hard to find a better example of Iowa’s diverse geological history than the Devonian Fossil Gorge. Here, visitors walk on a 375 million-year-old ocean floor and discover fossils of all kinds, including crinoids, horned coral, and brachiopods. Sturdy shoes are a must, since the bedrock here is uneven, and fossils are pressed into every crevice. Pat Witinok, a geologist and volunteer with the Army Corps of Engineers, compares it to the Grand Canyon. “Kids love it because it’s like a museum into the past,” she says. As visitors make their way down the gorge, they can see rocks that get progressively older, reflecting the law of superposition.
The gorge was exposed after the floods of 1993 and 2008, when water at Coralville Lake flooded the emergency spillway for days at a time, washing away trees, soil, and parts of the road, as well as exposing a chunk of Devonian-age bedrock. A brochure at the site explains that the fossils were preserved almost 200 million years ago before the dinosaurs existed. Click here for more interesting articles.
Driving directions from Paneless Window Cleaning LLC. to Devonian Fossil Gorge
Driving directions from Devonian Fossil Gorge to Lake Macbride State Park