Covered Bridges That Carry Traffic

The Lincoln County government built the Yachats (pronounced yah-HAHTS) Covered Bridge in 1938. Bridging the North Fork of the Yachats River, the road it carries ends a few hundred feet beyond the bridge. It serves two or three houses on that short stretch of road.

The late age of the bridge's construction would be remarkable in the East, but completely ordinary in Oregon. Very large native trees furnished the beam wood required for wood truss bridges, and the Oregon State Road Department published standardized designs. These bridges were cheap to build and strong enough to carry loaded logging trucks. Indeed, Yachats Bridge served logging sites more than it did through traffic (on a road so minor it eventually closed).

Once you are inside the cover you can see the main elements of a covered wood truss bridge: the trusses on the right and left (in this, as in nearly all Oregon bridges, a Howe Truss), a deck with heavy rails to keep traffic from crashing into a truss, and roof rafters looking much like the ones you'd see in your attic. The board-and-batten panels by the opening that look like doors that got caught inside the rails are there to give extra protection to the point where the truss and deck reach the ground.

Covered bridges nearly always are one lane wide. You sometimes get a lot of signs warning drivers about this. Nelson Mountain is a goodish sized rural community on the far side of the bridge. The road goes completely over the mountain to the town of Drain; it is so bad that I rate it as impassible by passenger cars, but the locals use anyway.

This bridge, built by Douglas County in 1943, crosses the Little River to reach the Cavitt Creek community. The county built it to carry logging traffic, and full logs were used for beams.

Pengra Bridge (named for a nearby railroad station) was built in 1938 as part of an early highway over the Cascade Range, now replaced by SR 58 nearby. It's one of a number of covered bridges near Eugene.

The curve in the approach road is caused by the road reaching the river at an angle, and then turning to go straight across it so that the expensive bridge is as short as possible. This is a common feature of bridges constructed before automobiles reached speeds above twenty miles per hour.

Goodpasture Bridge is Oregon's longest covered bridge in daily use on an important road, with a single span 165 feet long. It was built by Lane County in 1938 to cross the McKenzie River, linking a rural community with SR 126. It looks like it could snap like a twig, but in fact it carries logging trucks daily, and has for eighty years.

To look at it you'd think that it would have to be some sort of national record holder, but it's not. California's Bridgeport Covered Bridge has a single span over two hundred feet long, while New Brunswick's Hartland Bridge is 1,282 feet long in seven spans.

Office Covered Bridge, located near the Cascade Peaks, beats out Goodpasture for the title of the longest single span in Oregon. A logging company built it in 1944 to allow loaded trucks to reach a lumber mill and company offices, hence its name. You can still drive over it to reach a picnic area on the far side.

Here you can see how massively this very long bridge was built in order to handle heavy logging trucks.

You can also see a Howe truss in action. A truss uses a triangular design to transfer weight from the middle of the bridge to the land; the weight goes up one side of each triangle and down the other. In a Howe truss (invented in 1846), right triangles are used, with metal rods forming the upright side of the right angle. The metal rods pull the deck up towards the ceiling beams (called "upper chords"), then the wooden slanted members push that weight back onto massive beams ("lower chords") just under the deck. Then another set of metal rods pulls that weight back up onto the upper chord, and the next slanting beam pushes it back down to the lower chord. This continues for ninety feet in each direction, until the center's weight finally reaches land.

This is one of two covered bridges (Wendling is the other) serving a fairly extensive rural area just north of Eugene. It was built in 1938 by Lane County to replace an earlier structure. In 1964 the blockbuster Shenandoah (starring James Stewart) used it and a number of other nearby areas for location shooting.

This 1932 bridge is named for the rural community it serves, as well as the creek it crosses. It carried an important local road—and logging area feeder—up until 1970, when this great loop of Deadwood Creek was bypassed. It is still used by nearby residents.

All of these covered bridges have some sort of window cut into the sides. Here's a fall view over Deadwood Creek, from the windows in the Deadwood Bridge. Note the rods and braces for the Howe truss.

This is the companion bridge to Earnest Covered Bridge above. Together they link this fairly large rural community to the outside world, including nearby Eugene.

Short Covered Bridge crosses the South Santiam River off US 20 in the Cascades Range, giving access to Cascadia State Park. Nearby is another unusual wood truss bridge, the Cascadia Park Bridge, in which the deck sits on top of the wood truss, protecting it from the elements.

Short Bridge is one of several with little or no covering on its sides—just a roof.

Covered bridges need periodic repair—as do every other sort of bridge. The current Belknap Bridge dates only from 1966, its three predecessors having succumbed to the elements. It's been maintained in 1992, 2002, and here, in 2016. It crosses the McKenzie River off SR 126, twenty miles east of Goodpasture Bridge (above).

The State Road Department built the Coyote Creek Bridge in 1922 to carry traffic on what has been a major highway since before statehood, the 1854 Territorial Highway. This highway has since been rebuilt for modern traffic a short distance away, leaving the bridge to serve local residences.

To save money, bridge builders try to make the main (expensive) span as short as they dare, leading to long approaches like this. It's tricky. The entire point of using a truss is to make the bridge longer, and therefore keep its supports farther from the flooding river itself. Here you see a long approach to a bridge whose piers sit in the river. This is pushing their luck.

The State of Oregon built Grave Creek Bridge in 1920 to carry traffic on the highway that would, after several iterations, become Interstate 5. Indeed, it passed out of the state highway system only with the completion of Interstate 5, and still carries significant traffic. Like all covered bridges it's only one lane wide, leading to a fair amount of stopping and jockeying.

Like Wild Cat Creek (above), the Grave Creek Bridge has a long approach to a main bridge with piers in the floodable area.

Built in 1929 (or perhaps 1936, as there is debate on this point), Harris Bridge was built to carry US 20 over the Marys River west of Corvalis. US 20 has long bypassed this bridge well to its north, leaving this on a quiet and attractive backroad. An adjacent winery celebrates it with its name.

Located in the Willamette Valley northeast of Salem, the 1916 Gallon House Bridge got its name as a quiet, private place where liquor smugglers could transfer their goods from a wet town for sale in a dry one. It is the oldest covered bridge in the state that is still used for traffic.

The railings always found along the deck prevent vehicles from crashing into the trusses, and so damaging (or destroying) the bridge's structural integrity. They are very substantial.

The Shimanek covered bridge dates from 1966, replacing a 1927 span destroyed in a flood. It is one of six covered bridges clustered around the small town of Scio, northeast of Corvallis in the South Santiam River drainage.

Another one of the five Scio area bridges, the 1936 Hannah Bridge is open sided, like Short Bridge above.

Hannah Bridge—like the other bridges on this page—sits well above the flood. That's its purpose, the reason it exists. If the stream didn't flood the bridge builders could use the cheap and simple pier-and-beam construction, in which wood beams lay on top of piers. The problem with pier-and-beam is that, for anything other than the narrowest streams, one or more piers must sit in the water and this makes it likely that the bridge will be swept away in a flood. Modern pier-and-beam bridges, now very common, overcome this by using incredibly massive piers and beams whose great weight makes them unmovable, but this was not available in former times. The truss allowed the bridge to be extemely long, and thus stretch from bank to bank well above the flood.

The Scio area bridge builders liked the open sided covering, and used it for three of the five bridges (or four of the six if you include the nearby Stayton-Jordan Bridge, no longer open to traffic).

Larwood is the third of the Scio bridges with open sides. It sits on Fish Hatchery Road, a wonderful name.

Larwood has typical rafters for this area. The strong cross members hold the roof in tension, and so prevent it from sagging under snow loads. The Howe truss shows very well in this picture.

Hoffman Bridge was built in 1936, and was named for its builder.

The little-travelled road that Hoffman Bridge serves is called Hungry Hill Road.