Oregon Revised Statutes Mortgages and Liens § 86.040

No person shall sell, dispose of, remove or damage any building or other improvements upon mortgaged lands. All such improvements are deemed a part of the mortgaged property and are subject to the mortgage lien. When any improvements are removed from the mortgaged premises in violation of this section, the mortgagee may follow and regain possession of such improvements wherever found or may recover the reasonable value thereof from the person removing them.