San Joaquin Marsh Wildlife Sanctuary

The site is owned by the Irvine Ranch Water District; it was used for farmland in the 1950s and 1960s, and (prior to its reconstruction) as a duck hunting range.

[1] Now, the site serves a dual purpose of removing nitrates from the creek water and providing a bird habitat.

[2] A small hill at one edge of the site serves as an arboretum for non-native trees, planted for Earth Day in 1990.

While waterbirds such as herons, egrets, pelicans, sandpipers, ducks, geese, and kingfisher spredominate, monthly censuses have found over 120 species of birds, including terrestrial hawks, swallows, roadrunners, and hummingbirds.

[2][3][4] The sanctuary is open to the public daily during the daytime,[4] and has over 10 miles (16 km) of wheelchair-accessible hiking trails.