Oregon Revised Statutes Mineral Resources § 517.240

Upon failure of any co-owner of any mine to contribute that co-owner's proportion of expenditures required in assessment work, or to perform or pay for such proportion, the co-owners who performed or caused to be performed the labor or assessment work, may, at the expiration of the year for which the assessment work was performed, give the delinquent co-owner notice that the assessment work for that year has been performed, stating by whom performed, the amount of work performed and the dates between which it was performed; together with a statement of the amount due from the delinquent co-owner for the delinquent co-owner's proportion of the work, and requiring the delinquent co-owner, within 90 days from the date of service of the notice, to pay to the co-owners who performed or caused to be performed such work, the delinquent co-owner's proportion. The notice shall further state that if the delinquent co-owner fails or refuses to contribute the proportion due for the work, the interest of the delinquent co-owner in the mine will become the property of the co-owners who performed or caused to be performed the assessment work.