The Wilmington-Chillicothe-Logan Intrastate Air Quality Control Region (Ohio) consists of the territorial area encompassed by the boundaries of the following jurisdiction 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 Ohio: Clinton County, Fayette County, Highland County, Hocking County, Jackson County, Pike County, Ross County, Vinton County.