Caesar Creek Fossil Hunting Guide: Ordovician Fossils in Ohio
Use this guide to plan a fossil hunting trip to the Caesar Creek Spillway near Waynesville, Ohio. The spillway exposes Upper Ordovician marine rocks filled with brachiopods, bryozoans, corals, crinoids, gastropods, cephalopods, and occasional trilobites.
Key Takeaway: Caesar Creek is one of Ohio's best beginner-friendly Ordovician fossil sites. Stop at the Visitor Center for a fossil collecting permit, then search the designated spillway area for loose, palm-sized fossils that have weathered out naturally.
Quick Facts for Caesar Creek Fossil Collectors
Location: Caesar Creek State Park near Waynesville, Warren County, Ohio.
Age: Upper Ordovician, roughly 449 to 445 million years old.
Rock Units: Waynesville, Liberty, and Whitewater formations.
Best Known Fossils: Brachiopods, bryozoans, horn corals, crinoid pieces, gastropods, cephalopods, and trilobites.
Important: Obtain a fossil collecting permit at the Caesar Creek Lake Visitor Center before collecting.
Best Search Area
The designated spillway collecting area exposes fossil-rich Ordovician limestone and shale.
Best Method
Walk slowly and search exposed surfaces and loose, weathered pieces. No tools are allowed.
Good For Beginners
Common fossils are abundant, making this a good family-friendly fossil collecting site.
Collecting Limit
The permit rules note that fossils or fossil-bearing rocks should fit in the palm of your hand.
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Dr. Jay M. Lipoff , 2026
New Megalodon Book: Expert insight and vivid fossil photography strip away myths to reveal the true science of history's most fearsome shark.
Why Are There Fossils at Caesar Creek?
The Caesar Creek Spillway was created by the U.S. Army Corps of Engineers for flood-control work. When the spillway was cut, it exposed wide areas of fossil-bearing Ordovician limestones and mudstones.
During the Late Ordovician, much of North America, including Ohio, was covered by a shallow tropical sea. Sediments accumulated on the seafloor and eventually became the alternating shale, mudstone, and limestone layers exposed today.
The mudstones represent deeper-water conditions, while many of the limestone beds represent shallower-water or storm-influenced deposits. These storm beds, called tempestites, helped bury and preserve the marine animals that collectors find as fossils today.
The fossils record an ancient marine ecosystem with corals, brachiopods, bryozoans, crinoids, cephalopods, gastropods, and trilobites. The Cincinnati region is famous for these Ordovician fossils because the Cincinnati Arch lifted the rocks closer to the surface, allowing erosion and excavations to expose them.
Location: Where to Collect Fossils at Caesar Creek
Start at the Visitor Center
Before collecting at the spillway, stop at the Caesar Creek Lake Visitor Center to obtain a fossil collecting permit. The spillway is south of the Visitor Center, and the permit explains the collecting area and rules.
Caesar Creek Fossil Collecting Rules and Safety
Permit note: The rules below are based on the fossil collecting permit information included on the original page. Always follow the current instructions given by the Visitor Center when you get your permit.
No Tools
No breaking rocks, hammering, chiseling, or using tools in the collecting area.
Palm-Sized Pieces
Keep fossils or fossil-bearing rocks that fit in the palm of your hand.
Spillway Only
Collect only in the designated spillway fossil collecting area.
Stay Safe
Park in the designated area and do not climb the walls or debris below the walls.
How to Look for Fossils at Caesar Creek
Since tools are not permitted, fossil collecting at Caesar Creek is mostly careful surface searching. Go slowly, look closely at loose slabs and exposed bedding surfaces, and focus on palm-sized rocks that already contain visible fossils.
Early spring can be a good time to visit because winter freeze-thaw cycles help loosen rocks and expose fresh fossils. By mid to late summer, the easiest finds may be more picked over. Also look closely for small enrolled trilobites, which can resemble tiny brachiopods in the rocks.
Fossil Identification: Common Fossils Found at Caesar Creek
The Caesar Creek Spillway is known for abundant Ordovician marine fossils. Brachiopods and bryozoans are common, while trilobites are exciting finds that may take a little more patience to spot.
Recommended Ohio Fossil Books and Local Fossil Clubs
Recommended Book
Fossils of Ohio (Bulletin 70), edited by Rodney M. Feldmann, is a useful reference for anyone collecting Ohio fossils, including fossils from the Cincinnati Arch region. It includes detailed descriptions and images of many fossils found throughout Ohio.
Recommended Trilobite and Fossil Hunting Books:
The Trilobite Collector's Guide
Andy Secher, 2024
This book by Andy Secher, a leading trilobite collector, offers a captivating journey into the world of these ancient arthropods. With over 400 stunning photos, entertaining top-ten lists, invaluable collecting tips, and ways to spot a fake trilobite, it's a must-have for fossil enthusiasts!
Trilobites: Common Trilobites of North America (A NatureGuide Book)
Jasper Burns, 2000
An excellent guide for identifying North American trilobites, featuring meticulous line drawings and concise information on classification, geologic range, and distribution. Ideal for enthusiasts seeking detailed insights and accurate identification of these ancient arthropods.
101 American Fossil Sites You've Gotta See
Albert B Dickas, 2018
This is a great updated fossil sites book with at least one fossil site in each state. Each site is broken into 2 pages. One has detailed information, such as directions, GPS coordinates, formation information, etc...
The other is dedicated to images of the site and the fossils found there. It also gives information on fossil 'viewing' sites such as dinosaur trackways, museums, and active excavations.
Plus, my fossil photos are peppered throughout this book!
Dry Dredgers
A Cincinnati-based fossil club and resource for fossils of Ohio, with field trips in the Cincinnati region.
North Coast Fossil Club
A fossil club based near Cleveland that takes field trips to fossil sites in and around Ohio.
References
Coogan, Allan H. (1996). Ohio's Surface Rocks and Sediments. Chapter 3 in Fossils of Ohio, edited by Rodney M. Feldmann. Ohio Geological Survey, Bulletin 70.
Hansen, Michael C. (1997). The Geology of Ohio - The Ordovician. Ohio Geology, Ohio Division of Geological Survey, Fall.
