Milepost 31

Milepost 31 Information Center

Milepost 31 was an award-winning information center in Seattle’s Pioneer Square neighborhood. Between 2011 and 2017 it welcomed almost 80,000 visitors from nearly 80 countries to the neighborhood and the SR 99 Tunnel Project. The center got its name because of its proximity to milepost 31 on SR 99 as the highway winds through downtown Seattle.
The center highlighted the people and projects that shaped the land that became Pioneer Square, and provided an inside look at the SR 99 Tunnel Project. Milepost 31 featured history, artifacts and exhibits designed to broaden visitors’ understanding of the land beneath them. Tour guides also led approximately 1,730 free tours explaining the effort to replace the Alaskan Way Viaduct. The tours included a climb to a closed section of the viaduct, where members of the public could gaze down upon the tunnel's ever-changing south portal construction site.

Milepost 31 closed on November 25, 2017. Its exhibits have been preserved in a virtual library:

Why was Milepost 31 created?

The information center was required by a memorandum of agreement (pdf 510 kb) signed as part of the Alaskan Way Viaduct Replacement Project. The agreement was developed to address Section 106 of the National Historic Preservation Act, which requires agencies to take into account the effects of their projects on historic properties, such as those in the Pioneer Square Historic District.

Within the agreement, city and state preservation officers along with the Federal Highway Administration, national and local preservation groups, neighborhood organizations, and local tribes determined that a project information center was one way WSDOT could help keep Pioneer Square vibrant during construction. 

Award winner

The center exceeded the expectations of all parties involved in its creation, and won several awards along the way:

  • King County Executive's John D. Spellman Award for Exemplary Achievement in Historic Preservation, awarded in April 2012.
  • Washington Museum Association for Project Excellence, awarded in April 2012.
  • American Association for State and Local History merit award, awarded in May 2012.
  • History in Progress Award, awarded in May 2012.
  • Exemplary Human Environment Initiatives (FHWA), awarded in August 2012.