Platoro Dam (National ID # CO82911) is a dam in Conejos County, Colorado.The earthen dam was constructed between 1949 and 1951 by the United States Bureau of Reclamation with a height of 165 feet (50 m), and 1,475 feet (450 m) long at its crest. It impounds the Conejos River, a tributary of the Rio Grande, for irrigation water storage as part of the larger San Luis Valley Project.