The Northwest Mosquito Abatement District was organized in April, 1956 and formed by public election in nine townships. Boundaries encompass the Cook County townships of Barrington, Palatine, Wheeling, Hanover, Schaumburg, Elk Grove, Maine, 1 sq. mile of Norwood Park and 6 sq. miles of Northfield. This is a land area of approximately 242 sq. miles. The Northwest Mosquito Abatement District's main office is located in Wheeling and 2 seasonal auxiliary facilities located in Hoffman Estates, and Elk Grove.