From Wikipedia:
The Lost Creek Bridge is a wooden covered bridge located near Lake Creek, Oregon, United States, about 15 miles (24 km) ENE of Medford. The bridge is about 11.89 meters (39 feet) long, making it the shortest covered bridge in Oregon.
The bridge was added to the National Register of Historic Places in 1979,[1] and subsequently closed to vehicle traffic. A newer concrete bridge runs parallel and serves as a bypass.[2]
Truss
The truss of the bridge is a queen post-style, comprising two angled supports pushing against a horizontal "keystone" support. The design is made to extend a king post-style truss, but is only stable for short spans.
Roof
The shingled roof is arched in flying buttress style, and was restored in 1985.
Located on a quiet dirt road just SE of Lake Creek is Lost Creek Covered Bridge, the shortest covered bridge in Oregon and rumored to be the oldest covered bridge in Oregon. I located a PDF document that reads:
The Lost Creek Bridge, at 39 feet, is the shortest of all Oregon covered bridges. Since 1979, the structure has been closed to traffic with a concrete span handling the few vehicles each day.
Many Jackson County residents, including Shirley Stone, daughter of pioneer John Walch, claim the Lost Creek Bridge to have been built as early as 1878-1881. If authenticated, this would make it Oregon's oldest standing covered bridge.
Johnny Miller, the builder of the Lost Creek Bridge, also roofed the nearby span at Lake Creek in the 1880s, thus lending credence to a sign nailed on the bridge: LOST CREEK BRIDGE, BUILT ABOUT 1881. The span may have been partially or totally rebuilt in 1919, hence the official construction date in that year.
Features of the bridge include the usual county Queenpost design, a shingle roof and flying buttress braces. The rough wooden flooring consists of diagonal planking, and hand hewn truss members provide structural stability. A new roof was installed by local residents in 1985. Portal boards were added in 1986, restoring the look of the span in 1920 before accommodations were made for log truck traffic. The Walch Memorial Wayside Park abuts the bridge site. Descendants of John and Marie Newsome Walch built and maintain the park, which includes picnic tables, a bandstand, cooking areas, an early 1900s outhouse, and manicured flower gardens.
The bridge was nearly lost in the 1964 Christmas flood. As swirling waters and heavy debris lashed at its piers, residents and concerned bridge enthusiasts prayed during the night that the bridge would be saved. According to a local newspaper, the skies opened and the water receded as morning came. The journalist questioned, "Was the bridge saved by prayer?"
(Reference: Roofs Over Rivers, by Bill and Nick Cockrell)