Hidden in plain sight near rural Rockford Iowa (in western Floyd County near Mason City) lies a glimpse into Iowa’s ancient past. In October 2019, I took a trip there to explore a park that promised a unique time travel experience (powered by a little imagination and some science!). I was not disappointed!
This defunct clay mine is filled with fossils that you are free to hunt and take home (but not to sell!). Even my toddler found handfulls of “sheshels” all by himself on clay and fossil rich slopes like these. The bedrock here contains fossils made during the Devonian era, about 375 million years ago, when Iowa was a warm inland sea near the equator.
Those of us who grew up among carpets of corn and beans of course have a hard time imagining what a warm ancient sea might look like here. I spent a lovely evening on The Google looking up and drawing the living versions of the rocks we found. As a child, I couldn’t get enough of the ocean and the beauty of coral reefs. Little did I know I was living above an ancient sea with corals, ancient fishes, and many kinds of shells. You can read all about it and find fossil examples and illustrations at the park’s visitors center.
Another interesting glimpse into Iowa’s recent past can be seen in the old brick kilns that were connected to the clay mine that excavated the fossil gorge in the late 1800s. Rockford Brick and Tile Co. once stood here, but it’s post-industrial scar still remains. Signs along the trail explain the mining process and a little about the company. Well after the company closed, local enthusiasts who knew what treasure trove of fossils were uncovered worked to save the land from development and turn it into a county park.
One of the beehive brick kilns at Fossil and Prairie Park that was part of Rockford Brick & Tile Co.
Hikers will appreciate the miles of diverse prairie trails available at the park, including remnant prairie. The route is well-marked and carefully groomed with interesting and informative signage. Hike all the way to nearby Rockford along the old railbed trail that served the Rockford Brick and Tile Co. You will also find canoe access to the Winnebego River in the park.
Access to the fossil gorge is easier if you hike around the gorge along the prairie towards the brick kilns. There are no stairs or handrails, so wear sturdy shoes and proceed carefully. Fossils are especially abundant after a rainstorm, but the the clay mud at the bottom is sticky - watch where you go and don’t step in wet puddles. Read the informative signs above the gorge and go try to find your own treasures!
Fossil and Prairie Sticker available in the visitors center at the park and in this shop.