Walter's Mill Covered Bridge originally stood over Coxes Creek four miles south of Somerset. The Pennsylvania Department of Highways replaced it with a concrete bridge in 1961, and it was then moved to a private museum along Route 985. In 1970, it was donated to the Pennsylvania Historical and Museum Commission to become part of the Somerset Historical Center and was moved to its current location. Residents of Mod Township petitioned the Somerset County Court in 1853 to replace a deteriorated bridge, and after several attempts to gain approval, they awarded Jacob Walter a $318.00 contract to build it. The bridge was completed in August 1859. Its original specifications called for a span of 45 feet from abutment to abutment, with 8 feet on each end beyond the abutments for a total length of about 60 feet. It was to be built with white oak or white pine timbers, white pine siding boards no wider than 12 inches, and white pine lapped shingles. The bridge used a kingpost-type truss system, and laminated arches similar to Theodore Burr's arched design were added about 1905 to this bridge and many others throughout the county to accommodate heavier farm machinery on the roadways.