Family vineyards. Family stewards of the land for 4 generations. Our vineyards are located along the Columbia River of Washington State, a region renowed for long, hot days followed by a cool nights and an abundance of natural resources and fertile soil. The sum of all the components of our region brings an essence of balance, structure and elegance in our wines. - Willis Mercer, VP Sales & Marketing; Robert Mercer, Proprietor. mercerwine.com. Alcohol 14.5% by volume.