Find out how historic resources are identified and designated.
The City of Portland recognizes numerous classifications of historic resources as being significant to the history of the city and its different communities. Some historic resources have been designated and are subject to land use protections, while others have only been identified as likely eligible for designation and protection. A resource may carry more than one classification, such as a resource that was identified as significant and subsequently designated as both a Local Landmark and National Register resource. An interactive map of all historic resources recognized by the City of Portland can be viewed online.
National Register Properties and Districts
The National Park Service designates resources on the National Register of Historic Places with only minimal involvement from the City of Portland. Created in 1966, the National Register is often considered the “highest” form of historic resource designation in Oregon due to the program’s rigorous expectations for documenting the historic significance and physical integrity of the resources that are listed. Buildings, districts, sites, structures, and objects may be listed in the National Register.
To be eligible for listing, a resource must generally be more than 50 years old, convey historic significance, and maintain physical integrity. Historic significance may include:
- A connection with a historic event or trend.
- A notable historic person.
- An example of notable architecture, construction, design, or engineering.
- The potential to yield scientific information, such as an archaeological site.
Properties with demonstrated historic significance must also closely resemble their historic appearance to be eligible for listing. Evaluation of physical integrity includes the location, design, setting, materials, workmanship, feeling, and association of the resource.
Nominating a resource for listing in the National Register is a public process that can be initiated by anyone. However, owner consent is required for individual listing in the National Register and the implied consent of a majority of property owners is required for a district to be listed. Once a resource is listed in the National Register, it can only be removed if its integrity is lost (e.g. demolition) or its historic significance refuted by subsequent research.
The National Register nomination and listing process generally begins with preliminary research on and documentation of the resource in order for the State Historic Preservation Office to provide an initial determination of National Register eligibility. After determining a resource to be eligible for listing, the proponent prepares a National Register nomination in accordance with federal submission requirements. Once the nomination is complete, State Historic Preservation Office staff review the nomination for completeness. Following correction of any deficiencies, the nomination is forwarded for review by the Portland Historic Landmarks Commission and a hearing by the State Advisory Committee on Historic Preservation. Nomination recommended for listing by the State Advisory Committee are forwarded to the National Park Service for final decision. Completion of the entire National Register nomination and listing process can take a year or longer.
Local Historic Landmarks and Districts
The City of Portland designates Historic Landmarks and Historic Districts that are significant for at least two of the following areas:
- The importance of its designer, previous owners, or builder in local, state, or national history;
- The quality of its architecture or landscaping;
- The fact that it is one of a few remaining examples of a building type that is of significance in local, state, or national history;
- Association with a significant cultural or ethnic group; or
- The role it has played in shaping local, state, or national history
As with National Register resources, listing as a Historic Landmark or District requires the resource to retain sufficient physical integrity from the historic period. Local Historic Landmark and District designation requires the consent of all property owners prior to listing.
Local Historic Landmark and District nominations are considered by the Portland Historic Landmarks Commission through a Type III land use review, initiated by the property owner.
Conservation Landmarks and Districts
Conservation Landmarks and Districts are designated historic resources that are significant at the local level for establishing the character of the region’s districts and neighborhoods. Conservation Landmarks and Districts are reviewed using the same approval criteria and land use procedure as Local Historic Landmarks and Districts. Conservation Landmark and District designation requires the consent of all property owners prior to listing.
Historic Resources Inventory (HRI)
The Historic Resources Inventory (HRI) is the product of a citywide survey of potentially significant historic resources that were documented for their eligibility for future historic designation. Listing in the HRI is not a designation, but a determination of historic significance based upon initial research and documentation. Resources on the HRI that were found to be most significant were given a rank of I, II, or III; resources that had historic features but were not found to be significant were not ranked.
Surveying historic resources consists of both in-the-field evaluations of the physical integrity of individual resources, as well as preliminary research on the architectural, cultural, and historic significance of the resources. Following the survey process, resources are evaluated to determine historic significance. All surveyed resources can be included in the HRI, but only those determined to be eligible for historic designation can be considered “significant.”
The HRI was last updated in 1984. In response to recent changes in State Administrative Rules that had long limited the City’s ability to update the HRI, the Bureau of Planning and Sustainability in 2017-18 is undertaking a review of how best to update the HRI in future years.
For information on the land use protections that apply to different classifications of historic resources, visit the historic resource protections webpage.