ORS § 203.720
The electors of any county, by majority vote of such electors voting thereon at any legally called election, may adopt, amend, revise or repeal a county charter. The charter, or legislation passed by the county pursuant thereto, shall provide a method whereby the electors of the county, by majority vote of such electors voting thereon at any legally called election, may amend, revise or repeal the charter. The county charter and legislative provisions relating to the amendment, revision or repeal of the charter are deemed to be matters of county concern and shall prevail over any conflicting provisions of ORS 203.710 to 203.770 and other state statutes unless otherwise specifically provided by conflicting state statutes first effective after January 1, 1961.
ORS 203.720