The North Central Iowa Intrastate 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 Iowa: Butler County, Cerro Gordo County, Floyd County, Franklin County, Grundy County, Hamilton County, Hancock County, Hardin County, Humboldt County, Kossuth County, Mitchell County, Webster County, Winnebago County, Worth County, Wright County.