Township, Range, Section: The section-township-range legal description is useful for finding early land records—such as survey notes, donation land claims, homesteads, and early land transfers. One section is one square mile of land (640 acres).
Land Status & Cadastral Survey Records, Bureau of Land Management (BLM) Oregon/Washington:
Includes original cadastral surveys plat maps (also called township maps) and field notes. Survey plats are maps showing any land ownership occupants at the time of the survey; Field notes cover section boundaries and water courses (meanders) and provide detailed information about the land prior to development: for example, trees, some ground cover, creeks, other physical features, roads, Indian trails and existing land occupants at the time of the survey. These are the best sources documenting the pre-settlement natural environment. The area within the current Seattle City Limits was surveyed from 1855 to 1862.
General Land Office Records (GLO), Bureau of Land Management (BLM):
The Bureau of Land Management General Land Office Records website allows you to find the original transfer of land from the federal government to an individual owner or homesteader. The records show how the land was first acquired and the date of legal transfer. Different types of transfers (e.g., donation land claims, homestead grants, cash sales, and scrip/warrants) have different requirements and may produce additional records.
1889 King County (Anderson) Atlas, The Seattle Public Library:
A collection of maps for Seattle and King County showing the names of original property owners. The 1889 atlas shows property boundaries for individuals listed in the GLO/BLM database above.
1920 Seattle (Kroll) Atlas, Seattle Municipal Archives:
Each double page of this real estate atlas depicts one Section (divided into east and west) and shows building footprints, roads, plats, streetcar line routes, parks, schools, etc.
1937 Aerial Survey, King County Road Services Map Vault:
Aerial photographs of Seattle (and King County) created as part of the Land Use Survey project – a project of the King County Assessor and the federal Works Progress Administration (WPA).
King County Maps and Atlases, Historic Map Works:
This fee-based subscription site includes historic property maps and atlases for King County, Washington created between 1907 and 1996 by Anderson, Metsker, Kroll, Thomas Brothers, and others.