In Missouri, covered bridges first came into use in the 1850s as roads, railroads, and overland transportation became practical and important, with the state's first covered bridge 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 them in northern Missouri just after the Civil War, but fire, flood, abandonment, rerouting of once heavily used roads, and neglect reduced their number to eight in 1958 and only four still stand today. Of the four remaining bridges, three use the Howe-truss system and one, Union Covered Bridge, uses the Burr-arch truss. Union Covered Bridge, completed in 1871 by Joseph Elliot in Monroe County, is the only Burr-arch truss still standing in Missouri, measures 120 feet long and 17 feet, 6 inches wide, was built almost entirely of native oak except for cedar shingles, and has horizontal siding unlike the vertical siding of Missouri's other covered bridges. Sandy Creek Covered Bridge, a Howe-truss bridge originally built in 1872 on the Hillsboro and Lemay Ferry gravel road connecting Hillsboro and St. Louis, was washed away in May 1886, then salvaged and rebuilt that August, and was constructed of white pine. Locust Creek Covered Bridge, built in 1868 and also known as Linn County Covered Bridge, stands between Laclede and Meadville on what was once Route 8, is the state's longest covered bridge at 151 feet, uses a Howe-truss design, and is made largely of white pine, though its original pine siding has been replaced with cedar. Burfordville Covered Bridge, whose construction began in 1858 and is the oldest remaining covered bridge in Missouri, became an important toll-road link after the Civil War between Burfordville, Jackson, and Cape Girardeau, and this Howe-truss span was built mainly of yellow poplar cut along the Whitewater River.