San Diego Bay National Wildlife Refuge in Chula Vista encompasses approximately 2,620 acres of salt marsh, intertidal mudflat, and open bay water managed by the U.S. Fish & Wildlife Service to protect endangered species along the southern rim of San Diego Bay. The Sweetwater Marsh unit preserves critical nesting habitat for the California least tern, western snowy plover, and light-footed Ridgway's rail — species that rely on the same coastal ecosystem explored by visitors at Rohr Park and other South Bay green spaces. The refuge's Gunpowder Point tract takes its name from a 30-acre World War I–era kelp-processing facility that produced potash for the British Army, a historical layer that now underlies one of the last intact coastal salt marshes in the San Diego region. An active captive-breeding program for the endangered light-footed Ridgway's rail operates in partnership with the Living Coast Discovery Center, SeaWorld San Diego, and the San Diego Zoo's Safari Park, while the refuge's wildlife-conflict and injured-animal protocols coordinate with Chula Vista Animal Services for domestic-animal incursions into protected habitat. The South San Diego Bay unit adds 875 acres of open-water habitat supporting migrating shorebirds along the Pacific Flyway, with ongoing salt-pond and Otay River Estuary restoration projects returning an additional 125 acres of tidal wetland to functional marsh elevation.