Point Pleasant's Battle Monument State Park, also known as Tu-Endie-Wei, was dedicated on October 10, 1901 to commemorate the Battle of Point Pleasant, at the time claimed to have been the first battle of the Revolutionary War. It significantly predates the 1928 establishment of the West Virginia state park system. The park includes the tavern begun in 1796 by Walter Newman, later operated as a museum of local history by the Daughters of the American Revolution. The Marietta Manufacturing Company (shipbuilders) moved to Point Pleasant in 1915; the facility continued to build mine-planting vessels and other small ships through World War II, but closed in 1970. During World War II the West Virginia Ordnance Works manufactured TNT in Mason County about 5 miles north of Point Pleasant; it was later repurposed as the McClintic Wildlife Management Area as well as an industrial park. The county's worst disaster occurred on December 15, 1967, when the Silver Bridge, a link-suspension bridge which had connected Point Pleasant to Kanauga, Ohio along U.S. Route 35 since 1928, collapsed during the rush hour commute. The disaster killed 46 people and injured nine others, and drew attention to poor bridge maintenance practices, as well as bridge loads greatly exceeding their original tolerances. The important bridge was replaced two years later by the Silver Memorial Bridge, which stands today. In 1981, the West Virginia Department of Agriculture acquired land that had been farmed after the Civil War by General John McCausland, the last fully confirmed Confederate general to die. Added to the National Register of Historic Places in 2003, it now operates as Smithland Farm. The River Museum opened on May 1, 2004, but closed in 2018 after a disastrous fire. According to the U.S. Census Bureau, the county has a total area of , of which is land and (3.1%) is water. Prior to its establishment in 1804, the land that would become Mason County was part of the vast and largely unorganized territory claimed by Virginia west of the Alleghenies. It was attached to various counties beginning with Orange in 1834, Augusta in 1738, and Botetourt in 1770. Beginning in 1772, the portion of Mason County south of the Kanawha River was part of Fincastle County, the West Virginia portion of which became Monroe County in 1777. The remaining West Virginia portion of Botetourt County, including the northern part of present-day Mason County, became Greenbrier County in 1778.