Code of Federal Regulations Title 40. Protection of Environment § 40.52.1921 Classification of regions

Central Oklahoma Intrastate

I

III

III

III

I

Northeastern Oklahoma Intrastate

I

III

III

III

I

Southeastern Oklahoma Intrastate

III

III

III

III

III

North Central Oklahoma Intrastate

III

III

III

III

III

Southwestern Oklahoma Intrastate

III

III

III

III

III

Northwestern Oklahoma Intrastate

III

III

III

III

III

Metropolitan Fort Smith Interstate

II

III

III

III

III

Shreveport-Texarkana- Tyler Interstate

II

III

III

III

III