1930s survey of forest resources in Washington and Oregon interactive map

The first large-scale survey of forest resources in the Pacific Northwest began in the early 1930s in response to the passage of the 1928 McSweeney-McNary Forestry Research Act. The act authorized the creation of a forestry research program and directed the Secretary of Agriculture to “make and keep current a comprehensive inventory and analysis of the Nation’s forest resources.” Conducting the survey required using various methods to determine forest types and their boundaries. For example, field crew identified some forest type boundaries by navigating trails, roads, and ridges to gain vantage points. Field data was combined with existing records from timber cruises and aerial photographs to produce forest cover type maps of Oregon and Washington. 

The PNW Research Station Forest Inventory and Analysis program digitized the map data, but they were not widely available until published to CD-ROM in 2003 as part of a report by Constance Harrington. The 1930s Survey of Forest Resources in Washington and Oregon (PNW-GTR-584) included background on the 1930s survey as well as copies of early results, most of which are still not available in digital format except in the report. 

Twenty years later, and nearly 100 years since the original survey, these data are now viewable as an interactive map.

Visit the U.S. Forest Service Research and Development Data Archive to download the historical forest resource data. The map is also available there in .jpg format for use as an image in reports and presentations.