Mystery Bridge nr. 5: Orr Bridge

Photo courtesy of Clayton Fraser

This month is where a lot of mystery bridges come to light. When presented into the limelight, it is hoped that people with knowledge and stories will step up to the plate and shed some light on the structure. Minus the last entry, the fifth mystery bridge takes us back once again to Harrison County, Iowa, and to this bridge.

Located over four miles northeast of Missouri Valley over the Boyer River at 290th Avenue, this Pennsylvania Petit through truss bridge was one of the longest of the truss bridge types that existed in Iowa, with a span of 225 feet. The bridge was unique because of the Town Lattice portal bracing, as can be seen in the picture above. Most Pennsylvania Petit trusses in Iowa featured either an A-frame or a Howe Lattice portal bracing, which was typical, as these bridges are large and long on the one hand, but vulnerable to extreme weather and heavy loads to a point where the overhead bracing was not enough to support the upper trusses. Any portal bracing with diagonals were needed to reinforce the bridge and ensure that the Pennsylvania Petit did not blow over to the side.

Example of a Pennsylvania Petit with A-frame portal bracing: Thunder Bridge over the Big Sioux River west of Spencer, Iowa. Built in 1905 by the Clinton Bridge and Iron Works, the bridge is 181 feet long. Photo taken in August 2011

While almost all of the Pennsylvania Petits were constructed exclusively by the Clinton Bridge and Iron Company in Clinton, Iowa, it is unknown when the Orr Bridge was built, let alone who built it. Records indicated that the bridge was relocated from an unknown location in either Kansas or Missouri in the 1950s to replace a crossing that may have been one of many victims of the Great Flood of 1945 that wreaked havoc in western Iowa. But more information is needed to determine the bridge’s origins, let alone how it was transported into Iowa, like its counterparts, the California Bridge crossings and the Gochenour Bridge.

The story about the Orr Bridge ends on a sad note for it no longer exists. According to locals, it was destroyed by a tornado on 16 May, 1999 and despite pleas by the public to construct a new bridge, it fell on deaf ears by the county and the road was later abandoned. The Orr Bridge is one of the most unique bridges that existed in the county and one whose history is still open and left to be solved. To have a proper closing, here are some questions I have for anyone that has information about this bridge:

1. When exactly was the bridge relocated and who oversaw the relocation efforts,

2. Where (in Missouri or Kansas) did the bridge originate from,

3. When was the bridge first built and who built it, and

4. What is the story behind the bridge, both at its place of origin as well as in Harrison County prior to its tragedy in the hands of the tornado?

Any leads and information can be sent to the following e-mail address:  Looking forward to your comments on the bridge.


Interesting Fact: The tornado that annihilated the Orr Bridge was the same one that wreaked havoc on the county seat of Logan, indiscriminately damaging or destroying many homes and buildings. Many historic sites at the county historic village were either leveled or severely damaged. Two people were killed in the twister and many others were injured. The city has since recovered from that disaster. Another historic truss bridge at 8th Street was one of many structures that were spared by the tornado. It has now been closed to traffic.













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