San Luis National Wildlife Refuge, Nature reserve in Merced County, US.

San Luis National Wildlife Refuge lies in the floodplain of Bear Creek, Salt Slough and the San Joaquin River in Merced County, California. Its tree-lined channels, oxbows, wetlands and native grasslands are fed by a network of canals managed to grow food for migratory waterfowl. The refuge also holds the largest remaining network of native grasslands, shrubs and vernal pools in the Central Valley.

The refuge was established in 1966 as part of federal efforts to protect migratory birds during their winter stays and prevent conflicts with farming activities. The protection of these wetlands became urgent as agricultural development threatened their survival.

The refuge serves as an outdoor classroom where visitors learn about the relationships between water, plants, and animals in wetland ecosystems. Local communities connect with nature here and understand why these habitats matter for the region's wildlife.

The refuge operates year-round with a self-guided auto route and multiple nature trails available at no entrance fee. Visitors should bring binoculars and plan visits during early morning or late afternoon hours when wildlife is most active.

The tule elk herd here belongs to the smallest subspecies of North American elk; the animals were reintroduced to the refuge after the subspecies was brought close to extinction. Visitors sometimes spot them in the grassland sections rather than the wetlands.