Union Covered Bridge State Historic Site

After two uncovered bridges across the Elk Fork of the Salt River on the Paris-to-Fayette road failed between 1849 and 1870, the Monroe County court ordered a covered replacement in the spring of 1870, allocating roughly $5,000 toward it and a companion structure across the North Fork of the Salt River. Builder Joseph C. Elliott completed the span in 1871 at a cost reported at about $5,500, and the bridge opened on September 17, 1871. It was named for the nearby Union Church.

The structure is roughly 120 to 125 feet long, 17.5 feet wide, and 12 feet high, built largely of oak using treenails and minimal iron fasteners. Its Burr-arch truss is slightly bowed toward the upstream side, a design choice that helps stabilize the span in flood conditions. It is the only Burr-arch truss bridge remaining among Missouri's four surviving covered bridges.

By the early 1960s the bridge was nearly lost to neglect; in 1961 local residents raised about $1,000 toward its preservation, and in 1967 it was added to the state park system. That same year a flood damaged the bridge, and the following year repairs were made using timbers salvaged from the Mexico Covered Bridge, which the same flood had destroyed. The bridge was closed to vehicular traffic in 1970 and added to the National Register of Historic Places on June 15, 1970 (reference no. 70000342).

The span endured further flooding in 1988, 1993, and 2008, with a full restoration completed in 2019. Today it is preserved and interpreted by Missouri State Parks as the Union Covered Bridge State Historic Site, open to foot traffic and accompanied by interpretive signage describing covered-bridge engineering and the region's nineteenth-century road history.