Photo by Thomas A. Meyer/DNR
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.
Located on an extensive outwash sand terrace along the Wisconsin River, Avoca Prairie and Savanna contains 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 blue-stem, prairie cord grass, Indian grass, and sedges dominate the wet areas while little blue-stem, prairie drop-seed, and June grass are common 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.
From Avoca, go east on State Highway 133 1.5 miles, then north on Hay Road, across Marsh Creek, 0.8 miles to a mowed parking area in the southeast area 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.
Avoca Prairie and Savanna is owned by:
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 own custom map where you can zoom to a specific location, please use the DNR's mapping application.
Very few State Natural Areas have public facilities, but nearly all are open for a variety of recreational activities as indicated below. Generally, there are no picnic areas, restrooms, or other developments. Parking lots or designated parking areas are noted on individual SNA pages and maps. Trails, if present, are typically undesignated footpaths. If a developed trail is present, it will normally be noted on the SNA map and/or under the "Access" tab. A compass and topographic map or a GPS unit are useful tools for exploring larger, isolated SNAs.
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 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 fee. For more information, see Wis. Admin. Code NR 45. For non-DNR-owned SNAs, we are unaware of any vehicle or admission fees. However, please contact the landowner for more information.
In general, the activities listed below are 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.
Although a handful of sites allow activities like primitive camping (e.g. Lower Chippewa River on sand bars) or horseback riding (e.g. S. Kettle Moraine), the activities listed below are generally prohibited on DNR-owned SNAs.
For rules governing state-owned SNAs and other state lands, please consult Chapter NR 45 Wis. Admin. Code [exit DNR]