The Parkersburg (West Virginia)-Marietta (Ohio) 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 West Virginia: Jackson County, Pleasants County, Tyler County, Wetzel County, Wood County.
In the State of Ohio: Athens County, Meigs County, Morgan County, Washington County.