The 90th district covers all or parts of Amboy, Ashton, Byron, Compton, Creston, Davis Junction, DeKalb, Dixon, Earlville, Franklin Grove, Grand Detour, Hillcrest, Lake Holiday, Lee, Leland, Lost Nation, Malta, Mendota, Monroe Center, Nelson, Oregon, Paw Paw, Polo, Rochelle, Sandwich, Shabbona, Somonauk, Steward, Stillman Valley, Sublette, Waterman, and West Brooklyn.