The Yukon Delta National Wildlife Refuge is a United States National Wildlife Refuge covering about in southwestern Alaska. It is the second-largest National Wildlife Refuge in the country, only slightly smaller than the Arctic National Wildlife Refuge. It is a coastal plain extending to the Bering Sea, covering the delta created by the Yukon and Kuskokwim rivers. The delta includes extensive wetlands near sea level that are often inundated by Bering Sea tides. The refuge is administered from offices in Bethel.