DEQ's Eastern Region encompasses 18 counties of Central and Eastern Oregon (Baker, Crook, Deschutes, Gilliam, Grant, Harney, Hood River, Jefferson, Klamath, Lake, Malheur, Morrow, Sherman, Umatilla, Union, Wallowa, Wasco, and Wheeler).

Offices in Eastern Region issue air and water permits that limit the amount of pollution that industry or municipal sewage treatment plants can discharge to the environment.