Viaduct history

Traveling through Seattle's history from the Ice Age to the Space Needle:

This site is dedicated to the history of Seattle's downtown and waterfront, especially the State Route 99 / Alaskan Way Viaduct corridor. 


Milepost 31

Milepost 31 was located in Seattle’s Pioneer Square Historic District from December 2011 to November 2017. The center provided an inside look at the history of the neighborhood and the engineering behind the SR 99 tunnel.