Street layout of Seattle

The street layout of Seattle is based on a series of disjointed rectangular street grids. Most of Seattle and King County use a single street grid, oriented on true north. Near the center of the city, various land claims were platted in the 19th century with differently oriented grids, which still survive today. Distinctly oriented grids also exist in some cities annexed by Seattle in the early 20th century, such as Ballard and Georgetown. A small number of streets and roads are exceptions to the grid pattern.

Most streets in Seattle run either north–south or east–west. However, this orientation does not prevail in one of the oldest and densest parts of the town, bounded by Elliott Bay to the west, Broadway to the east, Yesler Way to the south, and Denny Way to the north. That exceptional area includes all of the Downtown Central Business District (CBD), the northernmost part of the Pioneer Square neighborhood south of the CBD, First Hill east of the CBD, and Belltown and the Denny Regrade north of the CBD.

The grid is oriented 32 degrees west of north in the southern portion of that exceptional area, and 49 degrees west of north in the northern portion. The two portions are divided by a line that runs along Stewart Street (or its right-of-way) from Alaskan Way on the Central Waterfront east to 3rd Avenue, then along Olive Way from 3rd Avenue to 7th Avenue, and along Howell Street from 7th Avenue to Denny Way.

These three grid patterns (due north, 32 degrees west of north, and 49 degrees west of north) are the result of a disagreement between David Swinson "Doc" Maynard, whose land claim lay south of Yesler Way, and Arthur A. Denny and Carson D. Boren, whose land claims lay to the north (with Henry Yesler and his mill soon brought in between Denny and the others): Denny and Boren preferred that their streets follow the Elliott Bay shoreline, while Maynard favored a grid based on the cardinal directions for his (mostly flat, mostly wet) claim. All three were competing to have the downtown built on their land. Denny prevailed in what would become the central business district, but it was Maynard's grid that ended up being extended throughout the city and into all of King County (60 miles east to west). Several cities in King County, such as Renton, Kirkland, and North Bend, have their own naming system and grid in the center of town, but Maynard's Pioneer Square based grid officially covers the entire county.

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