Otter Creek Bridge

Otter Creek Bridge

The North Branch Otter Creek Bridge in Greenwood County, Kansas, is a well-known, triple-arch stone bridge listed on the National Register of Historical Places. It was built by pioneer bridge builder Walter Sharp, as shown by the plaque. Walter Sharp is renowned for being the foremost builder of the famous Cowley County stone arch bridges. The Otter Creek Bridge actually replaced a previous stone arch bridge that only lasted a short time before succumbing to flooding. The replacement bridge is not, in the strictest sense, a true stone arch bridge. As can be seen in the photo below, the center of the arches are made of concrete, and everything else of stone. This method of construction is probably derived from Walter Sharp’s standard method of building stone arch bridges using mortar to make the angles of the interior archwork, while cutting the arch facing stones fairly precisely.

Otter Creek Bridge
The Otter Creek Bridge in 2018.

The Otter Creek Bridge is one of the few remaining bridges Walter Sharp built employing a series of highly rounded arches. Where a large waterway was critical, Walter Sharp seems to have favored this method of constructing a series of smaller, rounded arches on thin piers instead of one or several long, flat arches. The famous Dunkard Mill Bridge over the Walnut in Cowley outside of Arkansas City was an example of this kind of construction. Greenwood’s double-arch Fall River stone bridge shows this design as well.

When in 2004 the bridge was preserved, it was already deteriorating. Undermining of the piers was a major issue with this bridge. Since stone arch bridges were frequently built on shallow foundations, they are rather easily undermined by the water action, which is arguably the leading cause of stone arch bridge failure. To the best of our knowledge no action was taken or has been taken since to correct this foundational difficulty with the Otter Creek Bridge. A picture of the Otter Creek Bridge from about a hundred years ago shows the arches ending more or less level with a grassy streambed. Scour action has obviously changed Otter Creek significantly.