ORS § 323.600
If, under ORS 323.500 to 323.645, the Department of Revenue is not satisfied with the return of the tax or as to the amount of tax required to be paid to this state by any person, it may compute and determine the amount required to be paid upon the basis of the facts contained in the return or upon the basis of any information within its possession or that may come into its possession. One or more deficiency determinations may be made of the amount due for one or for more than one period. Notices of deficiency shall be given and interest on deficiencies shall be computed as provided in ORS 305.265. Subject to ORS 314.421 and 314.423, liens for taxes or deficiencies arise at the time of assessment, continue until the taxes, interest and penalties are fully satisfied and may be recorded and collected in the manner provided for the collection of delinquent income taxes.
ORS 323.600