A spatial database of historical fire in westside forests of the Pacific Northwest
| Authors: | Aaron Zuspan, Matthew Reilly, Andrew G. Merschel, Connie Harrington, Peter D. Teensma, Glenn P. Juday, Peter Impara, Raymond J. Davis, Alan W. Dickman |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Pacific Northwest Research Station |
| DOI: | https://doi.org/10.3955/046.099.0204 |
| Source: | Northwest Science |
Abstract
Recent fire activity across forests west of the Cascade Crest in Oregon and Washington (the “westside”) has increased interest in the region's historical fire regimes. Substantial spatial information exists describing the location, extent, and timing of historical fires in the region, but these records represent independent efforts at local-to-regional scales, with considerable variation in data resolution, methodologies, discoverability, and metadata. To address the need for a systematic dataset of historical westside fire, we compiled a spatial database of over 7,300 fire perimeters and burned areas covering 125,000 km2, sourced from 25 datasets including historical forest inventories, cohort age studies, fire atlases, and aerial photo interpretations. We provide metadata, documentation, and guidelines for applying and interpreting the database, as well as three case studies illustrating possible applications and potential limitations. While the database documents extremely large and well-known fires such as the Tillamook Burn and Yacolt Burn, it also points to the historical importance of smaller fires and patches of stand-replacing fire on the westside. The case studies demonstrate 1) historical variability in stand-replacing patch sizes during wind-driven fire events, 2) resilience to early 20th century fire along the North Santiam River of Oregon, and 3) the role of repeated fire in creating early seral landscape diversity in the Coast Range. By considering the strengths and weaknesses of individual sources and using multi-proxy corroboration to reduce uncertainty, this publicly available database provides opportunities for new insights into the geographic variability of historical fire regimes on the westside.
Key Points
We developed a spatial database of over 7,300 historical fire perimeters across western Oregon and Washington, available online at https://doi.org/10.5281/zenodo.19120166.
Historical sources vary in spatial and temporal confidence, but can be used effectively by considering those limitations and finding corroboration in complementary data like aerial photography and field measurements.
Case studies demonstrate the resilience of westside forests to stand-replacing fires that created early seral conditions across a wide range of spatial scales.