81.63—Metropolitan Fort Smith Interstate Air Quality Control Region.
The Metropolitan Fort Smith Interstate Air Quality Control Region (Arkansas-Oklahoma) has been revised to consist 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: Benton County, Crawford County, Sebastian County, Washington County.
In the State of Oklahoma: Adair County, Cherokee County, Le Flore County, Sequoyah County.