Tundra dominates the area with subarctic vegetation, upland heaths, and sedge and grass meadows. Willows and alders ring the mountain bases and line stream channels. The maritime climate is characterized by frequent storms with persistent clouds, high winds, and low temperatures. Precipitation averages 35 inches annually, falling on over 200 days during the year. Temperatures generally vary between 0 and 60 degrees Fahrenheit.
Spring is typically the driest season and fall the wettest.
Though its size is small, the Izembek Refuge is critically important to migratory waterfowl, especially the black brant. The refuge was established in 1960 to protect the Izembek Lagoon and its entire watershed. The lagoon, which is also a State Game Refuge and a designated Wetland of International Importance, contains one of the largest eelgrass beds in the world. Thousands of waterfowl, including nearly the entire population of black brant, converge on the lagoon every fall from their nesting areas in Canada, Alaska, and the Soviet Union. The brant feed on eelgrass for up to eight weeks before their mass exodus, generally on a night in early November, to the Pacific Coast states and Baja California.