40 CFR 81.165: San Joaquin Valley Intrastate Air Quality Control Region.

The San Joaquin Valley Intrastate Air Quality Control Region (California) 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 California: Fresno County, Kings County, Madera County, Merced County, San Joaquin County, Stanislaus County, Tulare County.

Kern County—that portion of Kern County which lies west and north of a line described as follows: Beginning at the Kern-Los Angeles County boundary and running north and east along the northwest boundary of the Rancho La Liebre Land Grant to the point of intersection with the range line common to R. 15 W. and R. 16 W., San Bernardino Base and Meridian; then north along the range line to the northwest corner of section 2, T. 32 S., R. 32 E., Mount Diablo Base and Meridian; then east along the township line common to T. 32 S. and T. 31 S.; then north along the range line common to R. 35 E. and R. 34 E.; then east along the township line common to T. 29 S. and T. 28 S.; then north along the range line common to R. 36 E. and R. 35 E.; then east along the township line common to T. 28 S. and T. 27 S.; then north along the range line common to R. 37 E. and R. 36 E. to the Kern-Tulare County boundary.