ORS § 308.545
For the purpose of arriving at the amount and character and assessed value of the property belonging to a company, the Department of Revenue personally may inspect the property, and may take into consideration the statements filed under ORS 308.505 to 308.674, the reports, statements or returns of the company filed in the office of any board, office or commission of this state, or any county thereof, the earning power of the company, the franchises and special franchises owned or used by the company, and such other evidence of any kind that is obtainable bearing thereon. However, no report, statement or return shall be conclusive upon the department in arriving at the amount and character and assessed value of the property belonging to the company.
ORS 308.545