The historic Wohler Bridge, a one-lane connector spanning the Russian River along the back roads between Forestville and Healdsburg will undergo a seismic retrofit the summer. The project received a green-light after the Sonoma County Board of Supervisors awarded an $18 million construction contract to Ghilotti Construction Company. The existing seismically deficient one-lane bridge, which was completed in 1922, will receive a new lightweight concrete deck, seismic isolation bearings and joints, steel truss reinforcement and foundation reinforcement designed to meet current seismic design standards for bridges.