High Quality Content by WIKIPEDIA articles! The Office Bridge (also called Westfir Covered Bridge) is a covered bridge in Westfir, Lane County, Oregon, U.S. crossing the North Fork Middle Fork Willamette River at the south end of the Aufderheide National Scenic Byway and edge of the Willamette National Forest. It is Oregon`s longest covered bridge at 180 ft (55 m), and is one of only two in the state using triple Howe truss construction. It is the only covered bridge west of the Mississippi River which has a separate pedestrian walkway.