Approximate location — plotted from published sources, not a site visit, and not a guarantee of access.
About 2,300 acres of cienega wetlands, mesquite, and desert scrub on the U.S.–Mexico border in the San Bernardino Valley east of Douglas form San Bernardino National Wildlife Refuge. It was established to protect perennial springs and endangered fishes of the Río Yaqui drainage and supports more than 270 bird species as a migratory corridor between Mexican and U.S. sky-island ranges. Dirt roads from the valley floor reach the main entrance; headquarters sits separately on Highway 191 north of Douglas.