Harrison is a town in Cumberland County, Maine, United States. Harrison is included in the Lewiston-Auburn, Maine metropolitan New England city and town area. The population was 2,447 at the 2020 census. A historic resort area, Harrison straddles Long Lake and Crystal Lake. It is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical ar…Harrison is a town in Cumberland County, Maine, United States. Harrison is included in the Lewiston-Auburn, Maine metropolitan New England city and town area. The population was 2,447 at the 2020 census. A historic resort area, Harrison straddles Long Lake and Crystal Lake. It is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area.