When the American Telephone and Telegraph Company (AT&T) created a universal North American telephone numbering plan for Operator Toll Dialing in 1947, Missouri was divided into two numbering plan areas (NPAs). Area code 816 served points generally north and west of Columbia and Jefferson City, while area code 314 served the eastern third of the state, including St. Louis. In 1951, area code 417 was created as the third code in the state, for southwestern Missouri, comprising the southern half of the original 816 boundaries.[1]
Despite the presence of Springfield, the state's third-largest city, 417 is one of the most sparsely populated numbering plan areas in the nation. Despite the growing proliferation of cell phones and smartphones (particularly in and around Springfield), under current projections southwest Missouri will not need another area code until about 2030.[2]
