Skip to main content

Theresa Marsh Wildlife Area


Theresa Marsh Wildlife Area is a 5,860-acre property that includes 5,309 acres of state-owned lands and 534 acres of permanent easements located in northwestern Washington and northeastern Dodge counties. The majority of the property is located along the west side of Interstate Highway 41 between Allenton and Lomira. Habitat consists of permanent wetlands (mostly cattail and brush marsh, the Rock River channel and runoff ponds), permanent grasslands, woodland, agricultural land and seasonally flooded wetlands.



A glacial lake with a southern outflow once occupied the site now known as Theresa Marsh. Subsequent glacial activity created the present outlet of the marsh flowing to the west and resulted in a vast tamarack and lowland hardwood river bottoms area that was logged during settlement times, leaving more or less open marshland. Over the years, various agricultural enterprises were attempted in drained portions of the marsh including cattle ranching, canary grass seed production, truck farming and mint farming, which ultimately failed due to short growing seasons and flooding risks. The Wisconsin Conservation Commission approved acquisition of the Theresa Wildlife Area in 1948. By the late 1960s, nearly 5,000 acres had been purchased. In 1968, a mile-long dike and concrete dam was constructed on the Rock River near Theresa Station on the west side of the marsh creating the current 1,500-acre main flowage.

Management objective

Theresa Marsh Wildlife Area is managed for wildlife production, as a migration stopover area for waterfowl and other birds, and to provide a variety of recreational opportunities (primarily hunting, trapping, fishing, bird watching, hiking and snowmobiling on designated trails). Over 75% of the wildlife area is emergent wetland, forested wetland or open water habitat. Following construction of the main dam in 1968, about 3 miles of additional dikes and 18 water control structures have been installed or enhanced around the perimeter, allowing water levels to be raised and lowered annually to manipulate wetland habitat. Water levels on the main pool and sub-impoundments are managed seasonally to provide optimal wetland habitat for ducks, Canada geese, herons, egrets, sandhill cranes, shorebirds and endangered black terns

Theresa is an important breeding area for dabbling ducks, especially blue-winged teal and wood ducks. Two waterfowl refuges (one on each end of the marsh) provide food and resting areas for long-distance migrants. The refuges are closed to waterfowl hunting at all times and closed to all entry from Sept. 1 through Nov. 15 each year. Refuge boundaries are posted with yellow "Wildlife Refuge" signs.

Pheasants are stocked for hunting twice each week during the first part of the pheasant season and once per week later in the season. Pheasant hunting is prohibited after 2 p.m., beginning the third day of the season through Nov. 3 (except on weekends). Natural fields, dike edges and sunflower fields provide opportunities for hunting mourning doves. Farmed fields of corn, hay, soybeans and other crops provide resting and feeding habitat for a variety of species. Permanent grasslands for nesting and hunting cover are maintained by periodic burning and/or mowing.


The Theresa Marsh Wildlife Area offers many recreational opportunities:

  • Boating (including electrical motors, but prohibited during the waterfowl season);
  • Birding;
  • Canoeing;
  • Cross-country skiing (no designated trail);
  • Dog training (class II) [PDF];
  • Fishing (limited);
  • Hiking (no designated trail);
  • Hunting (see note below);
  • Trapping
  • Wild edibles/gathering; and
  • Wildlife viewing.

Note: Please do not block access to gates. Target shooting (including paint ball guns), overnight camping, overnight parking, open fires, stocking or releasing any wild or domestic animals, bikes, horses, ATVs and other motor vehicles are prohibited.

Hunting note: Archery and firearm hunting are allowed on the marsh except in the two refuges that are closed to waterfowl hunting at all times and closed to all entry from Sept. 1 through Nov. 15 each year (posted "Wildlife Refuge" signs). The main huntable species are Canada geese, ducks, pheasants (2 p.m. closure rules apply), deer and turkey. Raccoons, mink, muskrats, coyotes, woodcock, cottontails, squirrels and other small game can also be found. Private land (posted with white signs) may be leased each year to provide additional public hunting and fishing opportunities. Do not enter private land without permission, including to retrieve game. All other activities (trapping, vehicle access, damaging trees, dog training, etc.) are prohibited on leased lands without the landowner's permission. Follow Wisconsin Hunting Regulations and do not discharge a firearm within 100 yards of a building. Portable stands may be used but must be completely removed from the property at the close of hunting hours each day.


Download maps of this property: northern section [PDF] and southern section [PDF].

If you are interested in exploring this property further, you can access an interactive map.

Useful links
Adopt a Fish or Wildlife Area


Find out more about how to adopt this wildlife area.