Monte Vista National Wildlife Refuge in southern Colorado’s San Luis Valley was established in 1953 to provide habitat for wildlife, especially waterfowl, within the Rio Grande watershed. Set on former agricultural land, it depends on intensive water management through dikes, canals, wells, and older irrigation works dating to the 1880s to create varied wetland habitats. The refuge is especially significant as a stopover for migrating greater sandhill cranes traveling between New Mexico wintering grounds and breeding areas in the northern United States and southern Canada, with as many as 20,000 passing through in spring and fall. Since the 1980s, it has also supported endangered whooping cranes and wintering elk.