 Hardin was murdered by Shawnee Indians while he was on a peace mission in 1792 for President George Washington, in what is now Shelby County, Ohio.In the 1790s and early 1800s, the Hardin County area, especially Cave-In-Rock, was notorious as a stronghold used by outlaws, bandits, river pirates, and counterfeiters.According to the U.S. Census Bureau, the county has a total area of , of which is land and (2.2%) is water.