Long before Door County’s forests, farms, and shorelines existed, the peninsula lay beneath a warm, shallow tropical sea teeming with life. Corals, crinoids, brachiopods, and other marine organisms thrived here hundreds of millions of years ago, leaving behind the fossils that can still be found embedded in Door County’s dolomite bedrock today. This week’s Summer at Crossroads theme, Fossils, invites visitors to uncover clues from Earth’s distant past and explore the ancient history hidden beneath our feet.
The week begins with a Tale. At 2 pm on Monday, August 17, “Curious About Fossils by Kate Waters” will be read aloud to participants. This engaging book introduces young readers to the fascinating world of fossils, explaining how they form and what they reveal about ancient life on Earth. Along the way, readers will meet famous fossil hunters such as Mary Anning, who discovered the first ichthyosaur skeleton, Richard Owen, who coined the word “dinosaur,” and Barnum Brown, who uncovered the first remains of a T. rex. The story also explores how modern scientists use technology to uncover clues from fossilized bones, teeth, and even footprints. For those unable to attend Story Time, the book will also be featured on our Trail Tales storybook walk available all week long beginning at the West Trailhead.
At 1 pm on Tuesday, August 18, Journeys with Joan will explore Finding Fossils. Naturalist Joan Wilkie will guide participants in discovering how plants and animals from an ancient sea became the fossils we find throughout Door County today. Visitors will learn how fossils form over vast stretches of time and gain a deeper appreciation for the marine life that once inhabited the region. As participants examine examples and explore fossil-rich landscapes, they will better understand the geological history that shaped the peninsula we know today.
On Wednesday, August 19, at 1:30 pm, participants in Wandering Wednesday will join a naturalist-led hike to look for evidence of Door County’s geological past. Along the trails, hikers will explore the landscape with fresh eyes, observing rock formations, exposed dolomite, and features influenced by ancient seas and glacial activity. The hike will highlight the connections between geology, fossils, and the modern ecosystems that have developed atop this ancient foundation.
The week concludes with a special Talk at 2 pm on Thursday, August 20. We welcome back Naturalist Coggin Heeringa who will present Ancient Silurian Seas, a fascinating journey back hundreds of millions of years to a time when Door County was covered by a warm, shallow sea. Participants will discover how coral reefs, marine invertebrates, and other sea life flourished here during the Silurian Period, long before dinosaurs or even land plants existed. The program will explore common local fossils such as corals, brachiopods, and crinoids, explaining how they formed, where they can still be found today, and what they reveal about changing climates and environments through time. Coggin will also connect these fossils to Door County’s distinctive dolomite bedrock, Niagara Escarpment, and shoreline landscapes, helping participants understand how the peninsula’s ancient past continues to shape the present.
Throughout the week—and continuing year-round during open hours—visitors can also enjoy Tinkers, our self-led, hands-on activities designed for curious minds. Guests can examine fossils, investigate ancient life forms, and explore the processes that preserve traces of organisms for millions of years.
Fossils are more than remnants of long-extinct organisms; they are records of ancient environments and evidence of dramatic changes across Earth’s history. In Door County, fossils remind us that our familiar landscape was once a tropical sea filled with life very different from what we see today. By exploring fossils, we gain a deeper understanding of the forces that shaped our region and a greater appreciation for the immense span of time recorded in the rocks beneath our feet.
Thanks to the generosity of our donors, we can offer free programming for all ages, and our trails are open all day, every day, free of charge.
ALL CONTENT © 2026 BY DOOR GUIDE PUBLISHING
