Oregon Fish Habitat Distribution.These data describe areas of suitable habitat believed to be used currently or historically by wild, natural, and/or hatchery fish populations. The term "currently" is defined as within the past five reproductive cycles. Historical habitat includes suitable habitat that fish no longer access and will not access in the foreseeable future without human intervention. This information is based on sampling, the best professional opinion of Oregon Dept. of Fish and Wildlife or other natural resources agency staff biologists or modeling (see the fhdBasis field). Due to natural variations in run size, water conditions, or other environmental factors, some habitats identified may not be used annually. These data now comply with the Oregon Fish Habitat Distribution Data Standard that was adopted by the Oregon Geographic Information Council in February 2011.

The Standard document can be found at: http://gis.oregon.gov/DAS/EISPD/GEO/standards/docs/OregonFishHabitatDistributionDataStandardv2.pdf Historical habitat distribution data are now within the scope of the standard and are identified via the habitat use (fhdUseType) attribute. Historical habitats are only identified outside of currently accessible habitat and are not comprehensive.Key features of the Oregon Fish Habitat Distribution Data include: species, run, life history, habitat use, origin, production, the basis for each record, originator name, originator entity and reference. Habitat distribution data are now mapped at a 1:24,000 scale statewide and are based on the Pacific Northwest Framework Hydrography dataset. The data are made available as GIS files that were developed over an extensive time period ranging from 1996 to 2013.