Park Ridge is an affluent Chicago suburb located 15 miles northwest of downtown Chicago. It is close to O'Hare International Airport, major expressways, and rail transportation. As its name suggests, Park Ridge lies on a ridge. The soil is abundant with clay deposits, which made it a brick-making center for the developing city of Chicago. The Des Plaines River divides Park Ridge from neighboring Des Plaines, which is west of Park Ridge. Chicago is south and east of Park Ridge, and Niles and unincorporated Maine Township are to its north.