There are 5 US Post Offices in Lake County serving a total of 9,901 residents equating to 1,980 residents per post office. It's estimated that approximately 15,803 packages are handled across the 5 county post offices annually. Lake County is a county located in the U.S. state of Michigan. As of the 2010 census, the population was 11,539. The county seat is Baldwin. The county was set off as Aishcum County in 1840. In 1843 it was renamed Lake, for its many lakes. It was organized in 1871"