Peak densities are reached in early May when as many as 100,000 waterfowl are using the refuge to feed, rest, and conduct their final courtship prior to nesting.
About 10,000 ducks — mostly mallards, pintails, and green-winged teal — remain to nest in the coastal fringe of marsh ponds and sedge meadows found in the refuge.
In the fall, migrant waterfowl and shorebirds once again arrive in growing numbers to rest and feed on sedge meadows, marshes, and intertidal mud flats.
The beluga gather in these nearshore waters to calve, breed, and feed on the large runs of eulachon (“hooligan”) fish that return to spawn in the Susitna River.
An impressive 40,000 user-days of sport fishing effort are expended on the Little Susitna River each year, reached over land on a rough 4-wheel drive trail.