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Avoca Prairie and Savanna

No. 68

Avoca Prairie and Savanna
Photo by Thomas A. Meyer/DNR

Located on an extensive outwash sand terrace along the Wisconsin River, Avoca Prairie and Savanna contain the largest natural tallgrass prairie east of the Mississippi River. Frequent flooding has created braided stream topography characterized by low, sandy ridges interspersed with small linear wetlands giving a local relief of 4 feet. The moist prairie and wetland swales contain more than 200 species of vascular plants including large numbers of rattlesnake master, Michigan lily, and prairie blazing star.

Big bluestem, prairie cord grass, Indian grass, and sedges dominate the wet areas while little blue-stem, prairie drop-seed, and June grass are standard on the drier ridges. Permanent and ephemeral swales contain aquatic species such as sweet-flag, yellow water buttercup, and common bur-reed. Some of the showy species include sweet grass, white wild indigo, flowering spurge, prairie smoke, bottle gentian, cardinal flower, and swamp candles. Oak openings, with large open-grown black and bur oaks, are an outstanding feature of this natural area looking much as they did during the original land survey of 1833.

Even today, from many points on the prairie, the same presettlement character has been preserved, with completely natural vistas still accessible in all directions. Avoca Prairie and Savanna is owned by the DNR and was designated a State Natural Area in 1968.

The good majority of SNAs are isolated and have few or no facilities. Some SNAs have vehicle access lanes or parking lots, but their accessibility may vary depending on weather conditions. Parking lots and lanes are not plowed during winter. Hiking trails may be nonexistent or consist of undeveloped footpaths. A GPS unit or compass and a detailed topographic map are useful tools for exploring larger SNAs.

Entrance fees: Excepting Parfrey's Glen, the Cambrian Outlook in the Dells of the Wisconsin River, SNAs within State Parks and some within State Forests, all other DNR-owned SNAs do not have any admission fees.

Allowable activities: DNR-owned land

The activities listed below are generally allowed on all DNR-owned SNA lands. Exceptions to this list of public uses, such as SNAs closed to hunting, are noted under the "Access" tab above and posted with signs on site.

  • Hiking
  • Fishing
  • Cross country skiing
  • Hunting
  • Trapping
  • Scientific research (permit required)
  • Outdoor education
  • Wild edibles (What is this?)
  • Pets (Rules)
  • Wildlife viewing

Prohibited activities: all SNAs

  • Camping and campfires
  • Collecting of animals (other than legally harvested species), non-edible fungi, rocks, minerals, fossils, archaeological artifacts, soil, downed wood, or any other natural material, alive or dead.
  • Collecting for scientific research requires a permit issued by the DNR
  • Collecting of plants including seeds, roots or other non-edible parts of herbaceous plants such as wildflowers or grasses
  • Geocaching
  • Horseback riding
  • Rock climbing
  • Vehicles, including bicycles, ATVs, aircraft, and snowmobiles except on trails and roadways designated for their use.

For rules governing state-owned SNAs and other state lands, please consult Chapter NR 45 Wis. Admin. Code [exit DNR].

Location

Within the Lower Wisconsin State Riverway, Iowa County. T8N-R1E, Sections 1, 2, 3, 12. T8N-R2E, Sections 5-8. T9N-R1E, Sections 34, 35, 36. 2,208 acres.

Driving directions

From Avoca, go east on State Highway 133 for 1.5 miles, then north on Hay Road, across Marsh Creek, 0.8 miles to a mowed parking area in the southeast region of the prairie. If the Marsh Creek crossing is impassable due to high water, vehicles must park in the lot south of the creek.

To access by canoe, put in at the Avoca Lake (Marsh Creek) boat launch and canoe downstream (east) approximately 1.5 miles to the road crossing and culvert. Walk north (~0.3 miles) into the prairie. The site is also accessible by canoe from the Wisconsin River.

The DNR's state natural areas program is comprised of lands owned by the state, private conservation organizations, municipalities, other governmental agencies, educational institutions and private individuals. While the majority of SNAs are open to the public, access may vary according to individual ownership policies. Public use restrictions may apply due to public safety, or to protect endangered or threatened species or unique natural features. Lands may be temporarily closed due to specific management activities.

Users are encouraged to contact the landowner for more specific details. The data shown on these maps have been obtained from various sources, and are of varying age, reliability, and resolution. The data may contain errors or omissions and should not be interpreted as a legal representation of legal ownership boundaries. To create your custom map where you can zoom to a specific location, please use the DNR's Mapping Application.

Property map [PDF]

Avoca Prairie and Savanna is owned by: Wisconsin DNR