Completed Project Report

Project Number: 1705-02
From Milepost: 2.510 To Milepost:2.570
Funds Paid: $ 2,800,000
Date Approved: 04/29/2005
Completed; 2008
Legislative District: 5

The SE Mount Si Road is a lifeline route offering sole access for close to 400 residents and visitors traveling in the area. Popular recreational use trailheads are located here within close proximity of Seattle, including Little Si and Mount Si trails into the Mount Si Natural Resource Conservation Area. The Mt Si bridge was originally built in 1914 and spanned the Green River but in 1955 was relocated to the SE Mount Si Road, crossing the Snoqualmie River. The bridge was designated as a County landmark and listed on the National Register of Historical Places for its engineering and architectural significance. The existing bridge and roadway was approximately 20-feet wide and did not accommodate pedestrians or bicyclists. Its overhead clearance and roadway width did not meet current standards for rural collector arterials. Because of these deficiencies – including rotting timber supports – the bridge was load limited and subject structural failure. The new bridge crosses the Middle Fork of the Snoqualmie River approximately 100-feet downstream of the old bridge location. The new 360-foot long bridge has two eleven-foot travel lanes, one eight-foot shoulder on the west side and a four-foot shoulder with six-foot sidewalk on the east side making travel for pedestrians and bicyclists safer and easier . Artwork was incorporated into many elements of the bridge including ornamental panels on the approach railings, landscaping elements, decorative bronze plates attached to the structure, bridge and railing paint colors and special finish and color applied to the bridge’s sidewalk. The new Pratt Truss replacement bridge won an award from the National Steel Bridge Alliance as the best medium size, steel bridge in the nation for 2009. A Community Advisory Group met periodically to provide input during the concept and design phases. Public support for the project was high.