Cienega del Oso is a swamp located in Rio Arriba County, New Mexico. It appears on the Polvadera Peak USGS 7.5-minute topographic quadrangle. The elevation at this location is approximately 10,410.24 feet (3,173.04 m) above sea level. The nearest populated place is Vallecitos Corrales, approximately 3.6 miles to the NE.