The refuge, originally named Mud Lake Migratory Waterfowl Refuge, was established in 1937 primarily for waterfowl production and maintenance. Located in eastern Marshall County, the contiguous 61,500 acres are situated in the aspen parkland region of northwest Minnesota. In 1976, 4,000 acres of the refuge were designated a Wilderness Area. Each year over 20,000 visitors enjoy wildlife viewing on Agassiz Refuge.

Today, Agassiz is composed of 37,400 acres of wetlands, 11,650 acres of shrublands, 9,900 acres of forestland, 1,710 acres of grassland, and 150 acres of cropland. The Wilderness Area encompasses one of the most westerly extensions of black spruce-tamarack bog in Minnesota. Two bog lakes, Kuriko and Whiskey, lie within the area.

WATER MANAGEMENT: Refuge wetlands are managed in 26 pools, ranging in size from 40 to 10,000 acres, through a complex system of dikes and water control structures. Management interfaces with Watershed District and State Department of Natural Resources wetlands and flooding issues. Pools are managed at various water levels from total drawdowns to full pool levels, simulating natural wet and dry cycles. Large pools are in total drawdown every 10 years; others every 2 to 6 years. Management is focused primarily on providing habitat for waterfowl broods and over-water nesting waterfowl, such as canvasbacks, ring-necked ducks, ruddy ducks, and redheads.

FIRE MANAGEMENT: Refuge staff use prescribed fire to discourage willow and other undesirable woody species on 1,000 to 10,000 acres each year. Burning keeps the areas open for waterfowl nesting. Fire is used in wetlands to enhance waterfowl habitat by breaking up dense stands of vegetation. It also helps maintain areas of young willow habitat to provide food for moose and white-tailed deer. Deer are the primary prey of wolves. Burning of reclaimed cropland stimulates native grasses. Oak-savannah habitat is maintained through periodic burning.

PRIVATE LANDS: The refuge is actively involved in restoring wetlands on private lands and working with other agencies in identifying wetlands, monitoring restored wetlands, and enforcing wetland regulations in seven counties.

WILDLIFE PROGRAMS: Annual censuses are conducted on breeding waterfowl, waterfowl broods, Franklin's gulls, several waterbird species, songbirds, deer, moose, and amphibians. Periodic surveys are conducted on wolves, black terns, and geese. Over 1,200 mallards are banded each year. Recent research projects on the refuge focused on moose, wolves, American and least bitterns, contaminants, and wilderness.