The ODNR Division of Geological Survey has studied Ohio’s bedrock geology since 1837. During that time, we have learned much about the state's geologic past. The bedrock we see today tells many stories of Ohio’s natural history. Many different environments have shaped the kinds of rocks we see in the landscape today. From shallow seas teeming with life to swamps and marshes, these environments and the geologic forces that acted upon them led to rocks such as limestones, sandstones, and shales that dominate Ohio’s bedrock.
Use the links below to learn more about Ohio’s bedrock geology and the Ohio Geological Survey’s efforts to research and map it.