There are 9 US Post Offices in Lake County serving a total of 286,312 residents equating to 31,812 residents per post office. It's estimated that approximately 456,986 packages are handled across the 9 county post offices annually. Lake County is a county located in the U.S. state of Ohio. As of the 2010 census, the population was 230,041. The county seat is Painesville. The county was established on March 6, 1840, from land given by Cuyahoga and Geauga Counties. Its name is derived from its location on the southern shore of Lake Erie. Lake County is part of the Cleveland-Elyria, OH Metropolitan Statistical Area."