The Northwest Arkansas 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 Arkansas: Baxter County, Boone County, Carroll County, Cleburne County, Franklin County, Fulton County, Izard County, Johnson County, Logan County, Madison County, Marion County, Montgomery County, Newton County, Pike County, Polk County, Scott County, Searcy County, Stone County, Van Buren County.