County of marker: Monroe County
Location of marker: MO C, Union Covered Bridge Historic Site, W. of Paris
Marker erected by: Missouri Department of Natural Resources, Division of State Parks
Covered bridges have existed for nearly all of man's recorded history. Ancient Babylonians are credited with having the first such structure over the Euphrates River about 783 B.C.. It continued to be a popular bridging method with similar bridges becoming common throughout Medieval Europe. Yet, it was not until 19th century America that the covered bridge idea reached its highest degree of use and design variations.
At the turn of the century, the steel and iron industry began to boom in the United States. It greatly influenced bridge design. Engineers began to rely less on wooden structures and more on modern metals. Combined with heavier rail and truck shipments and higher levels of traffic. wooden bridges became obsolete. The efw wooden bridges that remained were often bypassed with new roads and bridges.
In Missouri, the covered bridge was first used in the 1850s when roads, railroads and overland transportation in general became practical and important mode of travel. The first covered bridge in the state was built in 1851 in Boone County over Perche Creek on the Boone's Lick Trail. Eventually, 30 covered bridges were built in Missouri. Most of these were constructed in northern Missouri in the years just after the Civil War.
The ravages of time and progress took their toll on Missouri's covered bridge population. Fire, flood, abandonment or re-routing on once heavy used roadways and simple neglect left only eight covered bridges in the state in 1958; today only four are still standing.
Locust Creek Bridge:
This bridge was built in 1868. At 151 feet, it is the longest of the four surviving covered bridges in Missouri. Spanned Locust Creek, it once carried Route 8, the nation's first transcontinental highway.
Route 36, three miles west of Laclede; north on Danube Drive, one mile; then east on Dart Road.
Sandy Creek Bridge:
This bridge is a Howe truss bridge built originally in 1872 on the Hillsboro and Lemay Ferry gravel road that connected Hillsboro and St. Louis. This bridge was washed away by flood waters in May, 1886, but was salvaged and rebuilt the following August.
This former toll bridge was constructed of white pine. Although not a native to Missouri, this tree was, and still is, a common tree for lumber. The only native pine tree to Missouri is the short leaf, or yellow pine found in the Ozarks. Today, however, white pines can be found growing in Missouri everywhere.
Burfordville Covered Bridge:
The 140-foot Burfordville Covered Bridge, now preserved in the Bollinger Mill State Park, was a toll bridge, with a charge of 3 cents for walking travelers, 9 cents for a horse, and 37 cents for a one-horse carriage when it first opened in 1868.
Union Covered Bridge:
This bridge, completed in 1871 by bridge builder Joseph Elliot, is the only Burr Arch truss still standing in Missouri. Located eight miles southwest of Paris in Monroe County, the bridge measures 120 feet long and is 17 feet, 6 inches wide
Union Covered Bridge was built almost entirely of native oak. Oak is a common wood in northeast Missouri, easily available, hard, durable, and reasonably easy to work with. All of the wood used in Union Covered Bridge with the exception of the cedar shingles, is oak.
Another interesting feature of Union Covered Bridge is that the siding is horizontal, as it would be on a house; the other covered bridges in Missouri have vertical siding, as would be found on a barn.
In the 1800s and early 1900s, posters wee an important means of advertising that lined the roadways much like billboards do toady. The covered bridge, because of the protection it offered, became a prime spot for these richly colored advertisements.
Posters advertising everything from the latest miracle cure to the newest sewing machine, from the big circus coming to town to the best turnip seeds.
The many nooks and crannies is an uncovered bridge trapped dirt and moisture. This was ideal for decay of the timbers. Uncovered bridges exposed to the elements had a normal life expectancy of around ten years. Covered bridges roofed over to increase their longevity by protecting the trusses from the elements. As one contemporary expressed it, bridges were covered for the same reasons women wore petticoats - "... to protect their underpinnings." Other advantages also resulted:
1. The barnlike structures helped reassure farm animals about to cross.
2. The roofed structures served as emergency shelters.
3. The covering added to the strength of the bridge, reducing the sag and creaking commonly found in
uncovered wooden bridges.
Treenails (see gallery), pronounced "trunnels", were wooden pegs used in place of nails to hold the bridge together. Made on a lathe, they were anywhere from 1 to 2 inches in diameter and 10 to 12 inches long. As many as 900 treenails were used on a covered bridge 100 feet long
Scarf and stepped joints and lap joints (see gallery) were used to obtain chords of more than 100 feet. Both used on upper and lower chords are necessary in the construction of a bridge. A third joint, the mortise and tenon were used where web members connected to the kingpost.
Each truss member was individually fashioned simplified final assembly of the truss structure by stamping Roman numberals in the ends of the timber to be joined.