The 51st district, located in the Chicagoland area, includes all or parts of Arlington Heights, Barrington, Barrington Hills, Buffalo Grove, Deer Park, Forest Lake, Grayslake, Green Oaks, Gurnee, Hawthorn Woods, Kildeer, Lake Barrington, Lake Zurich, Libertyville, Long Grove, Mettawa, Mundelein, North Barrington, Tower Lakes, Vernon Hills, Wauconda, and Waukegan.