WSDOT imposes weight restrictions on Pierce County's historic Carbon River Bridge

Washington State Department of Transportation (WSDOT) bridge crews announced Thursday that effective immediately, no commercial vehicles will be allowed to cross the State Route 165 Carbon River Bridge until further notice. The restriction was prompted by the discovery late Thursday afternoon that one of the four vertical legs supporting the bridge’s approach span has loosened from its concrete footing, according to WSDOT officials. WSDOT bridge crews were en route to the bridge Thursday to examine the support and determine what repairs will be necessary before the restriction can be lifted.

WSDOT crews staffed each end of the one-lane bridge overnight to ensure that only passenger vehicles crossed the bridge. About 40 residents live between the bridge and the boundary to Mount Rainier National Park.

The single-lane bridge is located at milepost 11.5, three miles south of Carbonado in Pierce County. Aside from privately-owned logging roads, no detour is available for commercial vehicles.

According to WSDOT’s Web site, the 494-foot-long Carbon River Bridge was built in 1921, is included on the National Register of Historic Places, and is one of only two extant three-hinged steel arch bridges in the state of Washington. At the time of its construction it was the highest bridge in the state.

UPDATE — The Washington State Department of Transportation provided the following update on Fri., May 17 at 5:25 p.m.

At 5:15 p.m. today, Washington State Department of Transportation bridge maintenance crews completed repairs to a loosened support on an approach span of the State Route 165 Carbon River Bridge. The completed repairs reinstate full vehicular use of the bridge, including commercial vehicles. Over the last 24 hours, WSDOT has restricted use of the bridge to passenger vehicles only. The one-lane bridge, which is located at milepost 11.5 about three miles south of Carbonado, carries on average 250 to 300 vehicles a day. That number varies widely by season, however, since SR 165 provides access to the Mount Rainier National Park.