The Texoma AVA is an American Viticultural Area located in north central Texas, on the south side of Lake Texoma and the Red River that forms the border with the state of Oklahoma. The Texoma region is where 19th century viticulturist Thomas Volney Munson discovered that grafting Vitis vinifera grapevines onto native American varieties of vine rootstock resulted in vines that were resistant to phylloxera.