Agassiz

National Wildlife

Refuge

U.S. Fish & Wildlife Service

Agassiz National Wildlife Refuge

Route 1, Box 74

Middle River, MN 56737-9653

218/449 4115

Hearing impaired persons may contact 

Agassiz through the Federal Relay Number at 1 800/877 8339.

U.S. Fish & Wildlife Sevice

1 800/344 WILD

May 2000

Bullmoose

USFWS Photo
Agassiz is located 

in northwestern 

Minnesota in the 

aspen/parkland 

transitional zone 

between the coniferous 

forest, tall grass prairie 

and the prairie pothole 

region of the United 

States. 

Aspen/Parkland Vegetation

G. Tischer, USFWS
Agassiz: A Vital Link

Agassiz National Wildlife Refuge was 

established by Franklin D. Roosevelt’s 

Executive Order on March 23, 1937. 

Many refuges were established during 

the “Dirty Thirties” to counter the 

devastating effects of the Dust Bowl 

Era on people and wildlife when 

severe drought conditions dried up 

much of the nation’s midsection. Today, 

Agassiz is comprised of 

 40,100 acres of wetland, 

 10,000 acres of shrubland, 

 7,000 acres of forestland, 

 4,250 acres of grassland, and 

 150 acres of cropland. 

An additional 22,440 acres, managed 

by the Minnesota Department of 

Natural Resources, borders the 

refuge and creates 83,940 acres of 

unfragmented habitat for wildlife. 

Agassiz is located in northwestern 

Minnesota in the aspen/parkland 

transitional zone between the 

coniferous forest, tall grass prairie 

and the prairie pothole region of the 

United States. The area was formed 

by a glacier that encompassed an area 

larger than the size of the the presentday five Great Lakes. Meltwaters 

from the receding glacier created 

Lake Agassiz over 10,000 years ago, 

resulting in a very flat terrain varying 

from one-to-two feet per mile. 

In an effort to improve farming 

operations, an extensive drainage 

project was undertaken in 1909. By 

1933, over one million dollars had been 

spent trying to drain the Mud Lake 

area. Farming proved unsuccessful 

and Marshall County became so tax 

delinquent that the State Legislature 

appropriated $750,000 to save it from 

bankruptcy. In return, the State 

retained the right to use the lands for 

conservation purposes. Maintaining 

the land proved to be costly, and the 

State turned them over to the Bureau 

of Biological Survey (now the U. S. 

Fish and Wildlife Service) and the 

area became the Mud Lake Migratory 

Waterfowl Refuge in March of 1937. 

In 1961 the name was changed to 

Agassiz National Wildlife Refuge. 

Agassiz comes from the famous SwissAmerican naturalist/geologist Jean 

Louis Rodolphe Agassiz, for whom the 

prehistoric glacial lake was named. 

Today, Agassiz is one of more than 520 

national wildlife refuges totaling more 

than 93 million acres throughout the 

United States. The National Wildlife 

Refuge System is the only network of 

lands in the world primarily dedicated 

to the preservation and management 

of fish and wildlife resources.

Agassiz

NWR

Aerial View of Agassiz Pool

G. Tischer, USFWS

This “Blue Goose” 

symbolizes the 

National Wildlife 

Refuge System, a 

network of over 500 

refuges protected 

and managed for 

wildlife, habitat 

and people.
Managing for Diversity

The diversity of plants and wildlife is 

maintained by several management 

practices used to produce a diversity 

of wildlife habitats.

Upon establishment, wetlands were 

restored through a system of dikes 

and water control structures. Twenty 

pools have been developed ranging 

in size from 100 to 10,000 acres. 

Water management is used to create 

a variety of wetland types with a mix 

of emergent and submergent plant 

communities. Manipulating water 

levels is a vital management tool used 

to benefit waterfowl and shorebirds. 

The presence or absence of water, 

water depth and seasonal timing are all 

regulated to produce various stages of 

marsh habitat upon which these birds 

rely. Cattail is the dominant emergent 

plant in the wetlands. Bulrush, reed 

grass, white top, reed canary grass, 

spike rush and sedges are other typical 

emergent vegetation. The dominant 

submergent vegetation includes 

water milfoil, muskgrass, and sago 

pondweed. Abundant free floating 

aquatic plants include bladderwort, 

coontail and duckweed.

Revitalized 

Wetlands

Fires

Farming provides foods essential for 

waterfowl embarking on their annual 

migration south. Primary crops 

include barley, oats and winter wheat. 

Resident wildlife species also benefit 

from the farming program.

In 1976, 4,000 acres in the northcentral portion was designated as 

“Wilderness” and is managed under 

the National Wilderness Preservation 

System. It is one of the most westerly 

extensions of black spruce-tamarack 

bog in Minnesota. Two lakes in this 

area, Whiskey and Kuriko, were 

formed by deep peat fires which 

occurred prior to settlement of the 

area.

Farming 

Wilderness Area

Natural and man-made peat fires 

formed many of the smaller wetlands 

that dot the refuge today. Prescribed 

burning and brush mowing are tools 

used to maintain the grasslands and 

shrublands for nesting waterfowl as 

well as to provide habitat for moose 

and deer. This human intervention 

maintains the mosaic of grasslands, 

shrublands, forestlands and sedge 

meadows needed by native wildlife 

species.

G. Tischer, USFWS

Pitcher Plants 

W.D. Vasse

Canvasback Pair © S. Nielsen

USFWS 

J. Mattsson, USFWS
Wildlife

Agassiz National Wildlife Refuge 

provides a haven for many wildlife 

species. As many as 280 species of 

birds use the refuge; half which nest 

on the refuge. Forty-nine species of 

mammals, 12 species of amphibians 

and 9 species of reptiles also call 

Agassiz home.

The refuge supports 17 species of 

breeding ducks as well as giant 

Canada geese. In an average year 

7,500 pairs of ducks and 250 pairs of 

Canada geese nest at Agassiz. The 

diversity of wetland and upland 

habitat provides excellent protection 

for ducklings, goslings and molting 

waterfowl. 

Annual migrations bring peak 

numbers of waterfowl in May and 

October. Fall duck numbers can be 

as high as 100,000 and Canada geese 

25,000. The Eastern Prairie Population 

of Canada geese is the most abundant 

goose subspecies that migrates 

through Agassiz. 

Colonial nesting birds include large 

colonies that average 25,000 nesting 

pairs of Franklin’s gulls, 50-to-150 

nesting pairs of eared grebes and 

500 nesting pairs of black-crowned 

night herons. Smaller colonies of 

western grebes, great blue herons 

and double-crested cormorants also 

nest here.

For many years the average moose 

population on the refuge and adjoining 

state wildlife management areas was 

250. In 1993 the population declined 

sharply for unknown reasons; since 

1998 the population has slowly 

increased from its low of 50 animals!

Deer are usually abundant and have 

attained a peak population of 3,000 

animals. However, severe winters in 

1995-96 and 1996-97 reduced the herd 

to a record low of 430 animals.

Agassiz also has two resident packs 

of eastern gray wolves. These wolves 

roam the entire area during the winter 

months, but favor the grassland and 

forestland on the east and south sides 

during the rest of the year.

In 1992, after a 30-year absence, bald 

eagles began renesting on the refuge. 

Four pairs nested in 1999.

Photos: Common Yellowthroat, M.H.Lee; Mallards, S. Nielsen; Canada Goose and 

Franklin’s Gull, J. Mattsson, USFWS

Flock of Ducks

Photo: J. Mattsson, USFWS

Photos: Black-crowned Night Heron, ©B Silliker; Moose, G. Tischer, USFWS; 

White-tail Deer and Gray Wolf Pup, J. Mattsson, USFWS; Bald Eagles, ©S. Nielsen
Watchable Wildlife 

Viewing Opportunities

One of the most popular visitor 

attractions is the opportunity to view 

a moose in the wild. Although moose 

can be observed in all habitat types, 

focus your attention on willow thickets. 

September and October are the best 

months to observe moose.

White-tailed deer can be observed 

throughout the refuge and adjoining 

state wildlife management areas.

Gray wolf observations occur 

infrequently on and off the refuge. 

Bald eagles are observed most 

frequently during spring and fall 

migration. 

Canada geese start arriving in midMarch; ducks in early April. May 

through mid-June is the best time to 

observe ducks, when their colorful 

spring plumage makes identification 

easier. Goslings can be observed as 

early as the first week in May, and 

ducklings as early as the third week in 

May. Peak fall populations of Canada 

geese and ducks occurs from lateSeptember through October.

Best Wildlife Observation Periods

 Franklin’s Gulls: May 1-July 15

 Warblers: May 15-25

 Sandhill Cranes: April 25-May 5 and

 September 25-October 10

 Sparrow species: May 15-25

 Shorebirds: May 20-30 and 

 August 15- September 15

 Moose Calves: May 15-June 15

 Moose Rut: September 15-

 October 31.

Wildlife observation opportunities 

are best in the early morning or late 

afternoon hours, during feeding times. 

Staying in your vehicle and using it as 

a blind usually improves your chances 

of seeing wildlife.

Public Use Opportunities

Lost Bay Habitat Drive is a four-mile 

self-guided auto drive. Maakstad 

Hiking Trail is a quarter-mile 

foot trail along the auto drive. 

Headquarters Hiking Trail, a one-half 

mile self-guided foot trail, is located 

at Headquarters. The drive and trails 

provide opportunities for nature study, 

wildlife photography and observation. 

All are open from May through 

October during daylight hours. Hiking 

is only allowed on the drive and 

designated hiking trails. 

A 100-foot observation tower and a 14-

foot observation deck are available for 

viewing the refuge. Use of the 100-foot 

tower is permitted during the snowfree months, during office hours. A 

key must be obtained at the office.

9

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Snowshoe Hare 

J. Johnson, USFWS

N
Accommodations

Camping is not authorized on the 

refuge. Designated primitive camping 

sites, located on adjacent state wildlife 

management areas, are available year 

round and can be used free of cost. 

Camping with facilities are available 

at Old Mill State Park, 30 miles west 

of refuge headquarters, or in the Thief 

River Falls Tourist Park, 23 miles 

southwest of the refuge. 

The nearest motel accommodations are 

available in Thief River Falls, 23 miles 

southwest on State Highway #32 and 

at Grygla, 18 miles east of the refuge 

headquarters on State Highway #89.

Headquarters Location 

and Office Hours

Refuge headquarters is located 11 

miles east of Holt, Minnesota on 

Marshall County Road 7. Office 

hours are 7:30 am to 4:00 pm, Monday 

through Friday, excluding federal 

holidays. 

Need More Information?

For additional information contact: 

Refuge Manager

Route 1, Box 74

Middle River, Minnesota 56737-9653. 

Phone: (Holt) 218/449-4115.

Information on Agassiz National 

Wildlife Refuge can also be found on 

Agassiz’s Home Page

http://www.fws.gov/r3pao/agassiz/

index.html.

Equal opportunity to participate in, 

and benefit from the programs and 

activities of the U.S. Fish and Wildlife 

Service is available to all individuals 

regardless of age, race, religion, color, 

sex, national origin, or disability. 

Contact: U.S. Department of the 

Interior, Office for Equal Opportunity, 

1849 C Street, N.W., Washington, D.C. 

20240.

Available in alternate formats upon 

request.

Refuge Information

Information about Agassiz and the 

U.S. Fish and Wildlife Service are 

available at refuge headquarters 

and at kiosks along Marshall County 

Road 7. Exhibits of wildlife mounts 

are on display in the office building. 

Also, guidebooks and gift items can 

be purchased; proceeds help support 

activities on the Refuge!

Deer hunting is allowed during the 

regular firearm season in accordance 

with Minnesota’s deer firearm season 

regulations and special Refuge 

regulations. 

Several weekend events are held from 

May through October. Wildlife or 

plant related programs are presented 

at these events. Annual recurring 

events are International Migratory 

Bird Day (May), waterfowl banding 

(September), and National Wildlife 

Refuge Week (September/October). 

Check the Fish and Wildlife Service 

home page, http: //www.fws.gov/

r3pao/, for announcements pertaining 

to Agassiz and other National Wildlife 

Refuge events.

Schools, universities and other groups 

are welcome to visit and study nature. 

Tours, talks and demonstrations can be 

planned 

with staff members.

E

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Meadow Vole,

D. S. Licht
East

Olson

Lake

West

Olson

Lake

Whiteford 

 WMA

Mud Lac

WMA

Thief Bay

Pool Thief River

Tamarack

Pool

Northwest

Pool

Pool 8

Whiskey

Lake

Webster

Creek

PoolMud River

Pool

Middle

CCC

Pool

Kelly

Pool

Pool

21

Lower

CCC

Pool

Kuriko

Lake

Agassiz

Pool

Madsen

Pool

Lansing

Parker

Pool

Robert E.

Farmes

Marshall Pool

CR 120

Marshall

CR 7

Marshall

CR 121

Marshall

CR 123

South

Pool

Lost

Bay

East

Pool

Dahl

Pool

Elm Lake WMA

Eckvoll WMA

k

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West

 Gate

 Road

Thief

 River 

Road 

North

Gate

Road

Airport

Road

Maintenance

Center

Marshall

CR 7

0 1 2

Scale (Miles)

Open Water

Marsh

Upland

Wilderness Area

Refuge Boundary

State Wildlife Management

Area (WMA) Boundary

All Season Gravel Road

Seasonal Road

Refuge Headquarters

Observation Tower

Observation Deck

Hiking Trail

Information Kiosk

Lost Bay Habitat Drive

LEGEND

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q

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Co Rd 6

HWY 1

US 59

Greenbush

Karlstad

Holt

Newfolden

Gatzke

Middle

River

Roseau

Grygla

Thief Goodridge

River

Falls

HWY 11 HWY 32

HWY 89

Co Rd 6

HWY 1

Co Rd 12

HWY 32HWY 59

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Headquarters

Pool

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ThiefRive

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