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Wisconsin State Natural Areas Program Big Island (No. 384)

Big Island

Photo by Thomas A. Meyer/DNR



Within the St. Croix National Scenic Riverway, Burnett County. T41N-R15W, Sections 4, 5. T41N-R16W, Sections 1, 2, 11. T42N-R14W, Section 30. T42N-R15W, Sections 25, 31-36. T42N-R16W, Section 36. 1450 acres. Section 30. T42N-R15W, Sections 25, 31-36. T42N-R16W, Section 36. 1450 acres.



Big Island contains maturing examples of northern dry and dry-mesic forest, and northern wet forest along with forest seeps and a very diverse reach of the St. Croix River containing numerous aquatic invertebrates. The island rises about 100’ above the river and is forested with second growth aspen and paper birch with old-growth white pine and basswood occurring on north-facing slopes. Shrubs include nannyberry, American fly honeysuckle, eastern leatherwood, and northern bush-honeysuckle. The groundlayer is rich in plant species diversity and contains club-mosses, blueberries, maidenhair fern, wild sarsaparilla, blue cohosh, yellow-blue-bead lily, partridgeberry, and numerous spring ephemerals. The northwest and eastern tip of the island are lower and wetter with species such as white spruce, marsh bluegrass, northern blue flag iris, and wool-grass. Numerous seeps and north-south aspects add to the site variability creating numerous microhabitats for flora and fauna. Big Island is owned by the National Park Service and was designated a State Natural Area in 2002.


Driving directions

The area is best seen by boat. For walk-in access: from Riverside, go north on 35 across the bridge 0.7 mile, then east on Big Island Road 0.3 mile to an access lane. Cross the stream and walk south onto the island.


Big Island is owned by:

  • National Park Service


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.

Non-DNR lands

Entrance fees: For non-DNR-owned SNAs, we are unaware of any vehicle or admission fees. However, please contact the landowner for more information.

Hunting and trapping

This is a non-DNR owned SNA: Opportunities for hunting and trapping depend on the land owner. Please contact them directly to find out about their rules for hunting and trapping. You can find a link to other owner websites under the "Resources" heading above. More details regarding allowable uses of this non-DNR owned SNA may be posted, if available, under the "Access" tab above.

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Other activities

Other allowable activities such as - but not limited to camping, geocaching and bicycling are determined by the landowner. Please contact them directly or visit their websites for details.

Last revised: Monday, March 27, 2023