The Site consists of a freshwater lagoon and a floodplain located in the 1857 Constitución National Park. Laguna Hanson is the only semi-permanent natural lake in the forested areas of the state of Baja California, which are among the most southerly forests of the Nearctic biogeographic realm. The volume and duration of Laguna Hanson’s water give it ecological and biological importance, particularly for birds, as well as providing hydrological services to the populations downstream who use the Site as a source of water and food during the summer. The Site is designated as an Important Bird and Biodiversity Area (IBA) as it provides shelter, rest and breeding areas for at least 29 bird species, including migrants such as the gadwall (Anas streptera) and the redhead duck (Aythya americana). The vast majority of waterfowl recorded arrive during the winter and early spring. The main threats detected are fires and activities associated with visiting tourists, as well as extensive livestock farming, undertaken by the communities surrounding the National Park. A management plan, which includes a restoration plan, is being implemented.