The San Luis Closed Basin is a 2,940-square-mile (7,600 km2) endorheic basin in the Alamosa and Saguache counties of south-central Colorado. It includes San Luis Creek and its tributary, Saguache Creek. While the basin is east of the majority of the Rocky Mountains, it lies west of the Sangre de Cristo Range. An elevated plateau in Alamosa County, the San Luis Hills, separates the San Luis Closed Basin drainage from most of the San Luis Valley, which is southward-flowing and drains through the Rio Grande.[1]
- ^ "The Closed Basin Project". Rio Grande Water Conservation District. Retrieved June 25, 2023.