The Suiattle Road: why Boundary Bridge looks funny

By Kim Brown, Public Lands Intern

New Boundary bridge spanning the scoured channel. Photo by Gary Paull

The last Suiattle blog left us wondering about the delay torepair the Suiattle River Road. This article tells the story of oneparticularly unusual-looking bridge across the Suiattle and addresses one of themany factors in the repairs to the Suiattle River Road, the inclusion of theSuiattle in the Skagit Wild & ScenicRiver system (WSR). WSR designation preserves the free-flowingattribute of selected rivers – these rivers will never be impounded.Congressional wisdom enacted WSR as a counter –balance to its various actionsthat allow dams and other constrictions on rivers.

Constructedin 1959, the 240 foot-long Boundary Bridge spanned the entire river channel atmilepost 9.9, where FS 25 shoots off the Suiattle River Road, providing accessto the Circle Peak trail, Crystal and Meadow Lake trails, the Meadow Mountaintraverse, and tribal lands. The 2003 floods widened the river corridor and shiftedthe river south, leaving the bridge 165 feet short, and the river flowing infront of it, instead of underneath it.

Afterthe site was severely damaged in 2003, the Boundary Bridge repair work qualifiedfor funds from the Emergency Repair for Federally Owned Roads (ERFO). Projects inthe western region of Federal Highways that are funded by ERFO dollars aremanaged by the Federal Highways Western Lands Division (FHWA), who work withthe land agency on those projects.

WSRdesignation often requires special road and bridge design to maintain the river’s free flow, waterquality and other outstanding values, and Boundary Bridge was one such site. ERFO dollars pay for “in-kind” repair, meaningputting things back the way they were. FHWA’s repair design included a the re-buildof a new riverbank to close in the 165-foot gap left by the 2003 floods – puttingback what Mother Nature had ripped out (that’s a lot of dirt!).

The ForestService did not agree with FHWA’s design, which had the potential to adverselyimpact anadromous fish habitat and impair the river’s free-flowing attribute. Thenthe November2006 floods shifted the dynamic river back to its original channelunderneath the bridge,changing the repair site once again. In 2007, the projectwas put on hold and the excitement about the bridge repair fell silent.

In 2009, Peter Wagner, bridge engineer for the Mt.Baker-Snoqualmie National Forest (see page 3 of the linked article), designed a bridge extension that addressedthe WSR specifications by utilizing a lightweight material so that a pier wasnot necessary for support. Because the structural integrity of the original bridge was not compromised bythe floods, the old bridge was incorporated into the new design. The 210-footlightweight extension was “launched” from the end of the old bridge to the farbank, and then heavy equipment was driven across to finish the job. The lightweightmaterial used for the extension means that we have an odd-looking bridge – part1950s concrete, part new-age alloy with a high, criss-cross truss necessary forstrength and balance.

The BoundaryBridge repair was completed in 2010, providing not only visual entertainment, but access to the south side of theSuiattle for the first time since 2003.

Next time you're in the neighborhood, take the Suiattle River Road to milepost 9.9, and check out this bridge! (oh, and for the "it had to happen" files: there's a new washout on FS 25 at FS 2703. It's a nice drive across the Boundary Bridge - I like the way you sorta bounce onto the ramp at the new portion of the bridge)

Next up: What's the deal with the fish and Downey Creek?!