Document Type

Report

Publication Date

12-2011

Abstract

Mapping historical vegetation in Oregon and Washington has been ongoing since about 1993. It is based primarily on General Land Office (GLO) surveyors' descriptions of vegetation, recorded between 1851 and about 1940. For areas along the coast and the lower Columbia River, topographic maps ("T-sheets") of the U.S. Coast Survey (later called U.S. Coast and Geodetic Survey, and more recently the National Geodetic Survey)—based on field work conducted between 1852 and 1889—have been integrated whenever possible with GLO data because of their superior cartography and land cover symbology. For more detailed descriptions of mapping methods, see Christy and Alverson (2011) and Hickman and Christy (2011). A more detailed data entry guide is available on request from john.christy@pdx.edu.

Maps of historical vegetation are created in four steps: (1) transcription of GLO survey notes, (2) mapping and classifying historical vegetation based on GLO data, (3) integrating data and cartography from U.S. Coast Survey maps where available, and (4) digitizing the product to create a GIS layer.

Rights

This work is licensed under CC BY-SA 4.0

Persistent Identifier

https://archives.pdx.edu/ds/psu/44282

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