Anyone with even a mild interest in paleontology would enjoy a visit to the Devonian Fossil Gorge near Iowa City. Explore an ancient sea bed from nearly 400 million years ago, discover fossils, find evidence of tectonic forces at work, learn about its unique history, and enjoy the beautiful surroundings.
During a recent visit to Iowa City, our family stopped over to Devonian Fossil Forge to look for fossils. What a marvel! We had such a good time and made some amazing fossil discoveries.
Devonian Fossil Gorge
The Devonian Fossil Gorge is located at 2850 Prairie du Chien Road in Iowa City, Iowa. It is the emergency spillway area for the Coralville Dam.
Water flooded into the spillway in 1993 and again in 2008. Each time, these flood waters washed away soil and vegetation within the spillway and revealed fossil-laden limestone – an ancient sea floor from over 350 million years ago during the Devonian age.
You can walk around on this ancient sea bed and discover thousands of small fossils embedded within the limestone.
The Fossils
During our visit, we found fossilized coral, shells, various small sea creatures, primitive fish and even ancient worms.
The fossil find my family was most excited about was coral colonies of Hexagonaria. This fossilized coral features the same pattern as found in Michigan’s State Stone – the Petoskey Stone. Being from Michigan, our family has spent many hours looking for Petoskey Stones along beaches. The Petoskey Stone is also a fossilized type of Hexagonaria from the same time period (Devonian Period).
RELATED: How to Find and Polish Petoskey Stones
Other fossils you may find there include solitary coral (also known as “horn coral”), brachiopod shells, cephalopods, trilobites, sponges, and primitive fish.
IMPORTANT! Do not take any of the fossils you find at the Devonian Fossil Gorge. Removal of (or damage to) the fossils is strictly prohibited. Admire your fossil finds. Photograph them if you like. Just be sure to leave the fossils intact so that others can discover and enjoy them as well.
Geologic Structure
Besides the fossils, you may want to pay attention to the general structure of the ground beneath you.
The area is rife with faults, folds and karst. Look for these along the limestone floor you as you explore.
- Faults are cracks and fractures from where the rocks have moved.
- Folds are where tectonic forces have created a curved surface by actually forcing the rocks to bend.
- Karst is where parts of the rock have dissolved away from water running along fractures.
Coralville Lake Visitor Center
We didn’t even realize that there was a visitor center during our visit. It is kind of tucked away up a hill just east of the dam. We only learned of the Coralville Dam Visitor Center from reading brochures about the Devonian Fossil Gorge after we had already left the site. Don’t make the same mistake as us!
We have learned that the visitor center has some pretty interesting exhibits that we wish we had seen. It features artistically-rendered dioramas showing what the area probably looked like during the Devonian Period, preserved fossil specimens, video footage from the 1993 and 2008 floods, and more – even a skull from a giant 30-foot Devonian fish called a Dunkleosteus.
The Coralville Dam Visitor Center is located just up the hill from the gorge at 2850 Prairie Du Chien Road in Iowa City, Iowa. Visit the Coralville Lake Visitor Center website for hours and additional information.
Self-Guided Tour
Grab a Devonian Fossil Gorge brochure from the Coralville Lake Visitor Center. (Or, click here to access and print the Self-Guided Tour Brochure and Map (PDF) online.) This brochure features a numbered map, and the numbers on the map correlate with numbered markers within the gorge.
PRO TIP: Bring a magnifying glass with you to view fossils more closely.
I thought I saw something about an app for self-guided tours on one of the signs as well. That may be worth asking about in the visitor center.
Other Helpful Tips:
- Wear sturdy footwear for walking along the uneven stone ground.
- Be aware that the exposed limestone gets pretty hot on summer days.
- Consider bringing water with you. (Although, there is also a drinking fountain near the parking area.)
- Be sure to enjoy the surroundings around you. The lake views are quite nice. Plus, sometimes you can find small crayfish or tadpoles in the puddles of standing water in the gorge.
- The area is a great place to explore with children and dogs. (Dogs should be kept on a leash and cleaned up after.)
What Will You Discover at Devonian Fossil Gorge?
Would you enjoy exploring this ancient sea bed?
For more information, visit the Devonian Fossil Gorge website.
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Sounds fascinating
What a cool place to visit! My daughter would love this. We like learning about fossils while checking out the beauty of nature.
Oh my kiddo would love this so much!
This is fun! We like looking for fossil. Now I know a place to visit when we go to Iowa.
I was once in the hospital in Iowa City for a looong time. One day, the staff took us here for an outing of entertainment. I’d love to go back someday under MUCH better circumstances. Thank you for putting this together!
This looks like such a fun place to visit, especially for those who love fossils. My son would absolutely love this place. There are so many neat looking fossils there.
What a world of possibilities! Looks like a super fun place to explore!