Oregon Revised Statutes Revenue and Taxation § 312.214

(1) When a county has acquired or hereafter acquires real property by foreclosure for delinquent taxes, the county's title to the property shall have the utmost stability; and

(2) Once real property has become or hereafter shall become subject to foreclosure for taxes, there has been imposed and there hereafter shall be imposed upon all persons owning or claiming to own, or having or claiming to have, any interest in the real property, by reason of their delinquency, a continuing duty to investigate and ascertain whether the real property did become or hereafter shall become included in tax foreclosure proceedings, regardless of any defects, jurisdictional or otherwise, that may have appeared or shall hereafter appear in the foreclosure proceedings.