Homes for sale in Lewis County. Lewis County is located in northwestern New York State, slightly east of due north from Syracuse. The eastern part of the county is in the Adirondack Park. A good portion of the Tug Hill Plateau is in the western part of the county. The county is home to the Black River Valley.
As of the census of 2000, there were 26,944 people, 10,040 households, and 7,309 families residing in the county. The population density was 21 people per square mile (8/km²). There were 15,134 housing units at an average density of 12 per square mile (5/km²).