Oregon Revised Statutes Counties and County Officers § 215.253

(1) No state agency, city, county or political subdivision of this state may exercise any of its powers to enact local laws or ordinances or impose restrictions or regulations affecting any farm use land situated within an exclusive farm use zone established under ORS 215.203 or within an area designated as marginal land under ORS 197.247 (1991 Edition) in a manner that would restrict or regulate farm structures or that would restrict or regulate farming practices if conditions from such practices do not extend into an adopted urban growth boundary in such manner as to interfere with the lands within the urban growth boundary. “Farming practice” as used in this subsection shall have the meaning set out in ORS 30.930.

(2) Nothing in this section is intended to limit or restrict the lawful exercise by any state agency, city, county or political subdivision of its power to protect the health, safety and welfare of the citizens of this state.