Humedales del Delta del Río Colorado. 20/03/96; Baja California, Sonora; 250,000 ha; 31°50'N 114°59'W. Reserva de la Biosfera, Shorebird Reserve. A system of natural and artificial wetlands consisting of intertidal wetlands, brackish deltas, riverine environments, and permanent, freshwater lakes and ponds, set in one of the largest hydrographic basins in North America. Vegetation consists of diverse aquatic plants and coastal halophytic (salt tolerant) species, representing numerous endemic, rare or threatened species. Over 400 species of flora are present, with resident and migratory waterbirds representing the most important wildlife. Human activities include fishing, hunting, agriculture, scientific research, environmental education, ecotourism, and ranching. Small settlements of indigenous people are present. The delta, intensively modified due to agriculture and the lowering of the water table, represent the main threats. Ramsar site no. 814. Most recent RIS information: 2001.