Ohio once had more covered bridges than any other state, with a conservative estimate of over 2,000, and its remaining covered bridges are treasured artifacts from the past. State Route 26 features five covered bridges that reflect this part of Ohio's cultural heritage. Covered bridge trusses use an arrangement of posts, rods, and timbers in a rigid form so they support each other and the weight placed on the structure, usually through a triangle or a series of combined triangles, and different designers used different truss designs, including Long, Wernwag, Howe, Smith, and Multiple Kingpost trusses. The Hills Covered Bridge was built in 1878 by the Hocking Valley Bridge Works and features a Howe truss. When it was built, the bridge cost $13 per linear foot, and it was bypassed by traffic in 1990. The Cow Run Bridge once stood a few miles upstream from the Hills Bridge and was one of seven former covered bridges, now gone, that spanned the Little Muskingum River.