Lewis County, Missouri
Lewis County is a county located in the northeastern portion of the U.S. state of Missouri. As of the 2020 census, the population was 10,032. Its county seat is Monticello. The county was organized January 2, 1833, and named for Meriwether Lewis, the explorer and Governor of the Louisiana Territory.
Lewis County is part of the Quincy, IL–MO Micropolitan Statistical Area.