Dunthorpe Tree Protection: Heritage & Protected Trees Rules (2026)

Portland's Heritage Tree program, one of the oldest in the Pacific Northwest, was established in 1993 and is now codified in Portland City Code Title 11 Chapter 11.50. Trees are nominated by residents and evaluated by the Urban Forestry Commission based on: size (among largest of species), age (historic significance), unique form or species rarity, association with historic events or people, or exceptional community value. As of 2024, Portland has over 325 officially designated Heritage Trees on public and private property. Removal requires City Council approval after Urban Forestry Commission review - rarely granted except for imminent hazard. Private property owners can refuse Heritage Tree designation, but once accepted the protections run with the land. Pruning beyond standard maintenance requires city arborist approval. Construction near Heritage Trees requires a protected root zone barrier (typically 1 foot radius per inch of DBH). Unincorporated Multnomah County and other cities do not have formal Heritage Tree registries, but MCC 39.5500 protects Significant Natural Resource trees. Oregon Heritage Tree Program (OPRD) also recognizes state-level heritage trees, including several in Multnomah County.