The South Bend-Elkhart (Indiana)-Benton Harbor (Michigan) Interstate Air Quality Control Region consists of the territorial area encompassed by the boundaries of the following jurisdictions or described area (including the territorial area of all municipalities (as defined in section 302(f) of the Clean Air Act, 42 U.S.C. 1857h(f)) geographically located within the outermost boundaries of the area so delimited):
In the State of Indiana: Elkhart County, Kosciusko County, La Porte County, Marshall County, St. Joseph County.
In the State of Michigan: Berrien County, Cass County, Van Buren County.