Kanawha Falls is a waterfall on the Kanawha River in West Virginia, formed by a diagonal sandstone ledge that drops the river about 24 feet. Just below Gauley Bridge and near Glen Ferris, it has long served as both a landmark and a natural boundary. For more than 1 million years, the falls have limited fish movement, marking the upstream reach of several Ohio River watershed species while helping leave the waters above with fewer species but many found nowhere else. Altered by a 1920 overflow dam yet still central to hydropower, navigation, recreation, tourism, and river science, the falls remain a key reference point on the river.