Oregon Revised Statutes Crimes and Punishments § 167.238

(1) Proof of unlawful manufacture, cultivation, transportation or possession of a controlled substance is prima facie evidence of knowledge of its character.

(2) Proof of possession of a controlled substance not in the container in which it was originally delivered, sold or dispensed, when a prescription or order of a practitioner is required under the provisions of ORS 475.005 to 475.285 and 475.752 to 475.980, is prima facie evidence that the possession is unlawful unless the possessor also has in possession a label prepared by the pharmacist for the drug dispensed or the possessor is authorized by ORS 475.005 to 475.285 and 475.752 to 475.980 to possess the controlled substance.