Officials with the Washington State Department of Transportation have determined the Kummer Bridge is too unstable for traffic and closed the busy crossing over the Green River Gorge.

A press release issued Tuesday morning noted that the closure would be effective at 7 that night; further, it was stated that the bridge will remain closed for as long as six months.

The bridge, built in 1932 and home to approximately 9,000 vehicle crossings daily, has been the site of recent emergency work.

The state has been monitoring the slope under the southeast corner of the bridge since 1995 and, in early summer, noticed significant sloughing of the hillside. Interim repair work was quickly initiated and wrapped up just prior to the Fourth of July holiday traffic.

Work picked up again in late August. Crews were to drive 90 specialized soil nails into the hillside. The slope was to be covered with metal screening and a spray-on concrete. About two acres of hillside were scheduled to be treated.

The heavy rainfall that began Nov. 12 kicked off the latest troubles. The bridge was closed the afternoon of the 12th and didn’t open again until 6 p.m. Saturday. By Tuesday morning, DOT’s geotechnical experts had made the call for a long-term closure.