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Seattle Annexation Map gets new life from the City’s GIS team

The Seattle IT department would be remiss if we did not acknowledge that we are on the traditional land of the first people of Seattle, the Duwamish People past and present, and honor with gratitude the land itself and the Duwamish Tribe.

Seattle is a bustling city known for technology, coffee, and, recently, a new hockey team that is leaving its mark on the sport. Hemmed in by water on both sides, it’s hard for the city to grow — though we are experiencing growing pains. Seattle’s familiar hourglass shape is known to most residents, but are you familiar with how the City of Seattle expanded its boundaries back when the city was known as the last stop before heading to the Alaska goldrush?

The City of Seattle was first incorporated in 1869 and gradually grew by annexing neighboring cities and pieces of land (sometimes even by a single parcel!) through legal descriptions in ordinances. You can check out these ordinances on the City Clerk’s Office website.

A photo of an old City Ordinance with small type on a faded document.
An ordinance annexing the North Seattle territory to the City of Seattle.
a screen shot of a website with a map of Seattle, with areas of the city marked for annexation.
A GIS map

Photo credits:
An ordinance annexing the North Seattle territory to the City of Seattle.
City of Seattle, WA, Ordinance No. 1695, May 2, 1891
Credit: City of Seattle, Office of the City Clerk

Recently, the City’s Geographic Information Systems (GIS) team redesigned the City’s static vintage map into an interactive map highlighting Seattle’s annexation growth. Allen Grissom translated the hundred-year-old legal descriptions into their corresponding polygonal shapes. At the same time, his teammate, Nathan Schilling, used that dataset to create a user-friendly interactive map. Visit the new annexation map to see how Seattle has grown over the years.

a screen shot of a website with a Seattle Annexation History map

Written by Catherine Wendland, GIS Analyst, Seattle IT GIS Team.