The Izembek National Wildlife Refuge established in 1960 is one of the most ecologically unique of Alaska's refuges. Most of the refuge was designated as Wilderness in 1980 under the Alaska National Interest Lands Conservation Act. This diverse wilderness protects a wide variety of fish and wildlife species and their habitats. At the heart of the Refuge is the 150-square mile Izembek Lagoon. Shallow, brackish water covers one of the world's largest beds of eelgrass. The Refuge’s ecosystems comprise numerous lagoons, streams, and wetlands; coastal dunes and rock cliffs; large expanses of tundra uplands; alder shrub land mosaics; and the rugged Aleutian Mountain Range.