Important Bird Areas

St. Croix - Wild River S.P. IBA


The USGS maps are attached in Appendix A. Both maps clearly delineate the boundaries of the park. One contains an overlay of biodiversity significance and the other contains an overlay of plant communities.

The proposed Important Bird Area (IBA) is located northeast of Minneapolis/St. Paul on the eastern border of Minnesota along the Saint Croix River. It extends roughly 24 miles north from the Xcel Energy hydroelectric dam at Taylors Falls, MN, to the northern edge of Wild River State Park in Chisago County, MN. For the first 8 miles, from Taylors Falls to the southernmost edge of Wild River State Park, the IBA lies generally between County Road 16 and the center of the St. Croix River or the border between Minnesota and Wisconsin. For the last 16 miles, from the southernmost to the northernmost edge of Wild River State Park, it lies generally between the western edge of Wild River State Park and the center of the St. Croix River or the border between Minnesota and Wisconsin. Specifically, this IBA includes all land within the St. Croix National Scenic Riverway, Wild River State Park, and Lion?s Park.

The proposed IBA can be accessed either by boat or by car, generally from Chisago County Road 12, Chisago County Road 16 (Wild Mountain Road), or Chisago County Highway 9. Parking areas are located in Wild River State Park, on pull-offs along CR 16, and in Lion?s Park. Boats can be launched from two landings in Wild River State Park or at the Lion?s Park landing, roughly 1.5 miles upstream from the dam: Wild River State Park also offers canoe camping along the Saint Croix River. Skiing, biking, hiking, snowshoeing, and horseback trails are located in the state park, and informal trails exist in the area of the dam and Lion?s Park. County and local roads also traverse parts of the area.

The proposed IBA lies along the St. Croix River within the Anoka Sand Plain and Mille Lacs Uplands subsections, a region on the southern edge of the transition zone of pine forest, hardwood forest, and oak savanna. It encompasses a wide variety of habitats, including oak savanna, floodplain forest, maple-basswood forest, oak forest, two types of hardwood forest and, at its northernmost edge, conifer swamp forest. In short, this IBA transitions through three major forest types that divide into at least seven distinct habitats in only 24 miles of river.
From roughly County Road 16 south, the land drops steeply toward the St. Croix. Upland areas contain oak forest, but lowland hardwood forests predominate here, interrupted by scattered maple-basswood forest patches. The hills, bisected by ravines, are covered with black and green ash, aspen, bur oak, maples, slippery elm, and aspen. Northern pin and red oak trees are common at scattered locations within these forests, as are white and red pine trees. The dirt here is richer and loamier than it is farther north and the hills, though covered with soil, are higher and steeper.
North of County Road 16, smaller, gentler hills replace the larger hills and bluffs of the lower St. Croix River valley. Wild River State Park sits on a smooth, sandy plain once overlain by glacial Lake Grantsburg. Uplands are generally covered with oak savanna and oak forest in drier areas, where red oak, pin oak, burr oak, and white oak are common, though aspen and red maple can be found here as well. Lowland hardwood forest predominates near the river, with scattered maple basswood and white pine hardwood forest in mesic and river terrace areas. Sugar maples, green ash, big-toothed aspen, and slippery elm are common, as are red maple and clumps of paper birch where the ground shades into mixed hardwood swamp. The floodplain or riparian forest is dominated by silver maple, green ash, and lesser concentrations of burr oak trees. Wetland areas are also found in the floodplain: typically sedge meadows or marshes that inter-grade with shrub swamps. Wild River State Park is actively involved in expanding, managing, and maintaining native prairie areas as well ? the par?s middle section, in particular, contains open treeless areas scattered throughout its upland portion.
In the northernmost part of the IBA, forested wetlands replace much of the oak and lowland hardwood forest. The soil is darker and richer here: typical hardwood swamp vegetation includes birch, maple, aspen, black ash, and groups of large white pines. Floodplain forests and wet meadows are common near the river, a tamarack swamp can be found at the northernmost edge of the proposed IBA, and an emergent marsh follows Goose Creek, which drains into the St. Croix here. This part of the IBA is the most remote and hardest to access. Its rich, loamy soil, lowlands, and poor drainage also make it the wettest.

Ornithological Summary

The proposed Important Birding Area has three prominent features: the St. Croix River, the area?s exceptional biodiversity, and the convergence of two major life zones ? the Carolinian, from the south, and the Boreal, from the north. These three features combine to produce exceptional bird habitat, as reflected by the over 200 species of birds recorded within this IBA,
The St. Croix River, a federally protected National Scenic Riverway, is often identified as one of the Upper Midwest?s most pristine large river ecosystems. In just 164 miles, it crosses three forest types and two major life zones, which meet in the proposed Important Birding Area located within Wild River State Park. The river and its environs provide important nesting habitat and a migratory flyway for a wide variety of birds.
The MN County Biological Survey has classified slightly over half the habitat within Wild River State Park, which comprises most of the IBA, as being of "Outstanding" biodiversity significance. Roughly ¾ mile north of the hydroelectrical dam, another area of exceptional diversity runs north for 2 ¾ miles. The Minnesota DNR identifies the area as rich in key habitats for supporting Species in Greatest Conservation Need (SGCN). The greatest number of species and habitat occur directly along the St. Croix River, within the proposed IBA.
In addition to the proposed IBA?s spectacular river and outstanding biodiversity, it is located south of Crex Meadows, a natural ?duck factory? home to roughly 270 species of birds, and has at least two stretches of river that are open throughout most of the winter. This combination of diverse habitat, location, and open water makes the proposed IBA an important stopover point for migrating and over-wintering birds, including swans, geese, ducks, eagles, warblers, vireos, thrushes, flycatchers, and sparrows.

Conservation Issues

Cell towers, wind towers, and power lines are proposed along the bluffs overlooking the St. Croix River nearly each year. Xcel Energy and Dairyland power are continuing to push for construction of a large power line at or just below the proposed IBA?s southernmost border.

Deforestation is linked to housing developments; however, most of the area within the IBA is protected by Wild River State Park. The area immediately outside the park faces intense development pressure, although areas adjacent to the St. Croix River are protected by a combination of County and Federal regulation.

Disturbance to birds is associated with recreational use of the river; however, the upper St. Croix sees much less intense recreational use than the lower St. Croix.

Urbanization. Although the area within Wild River Park is protected, land outside the park and immediately adjacent to the IBA faces intense development pressure. Issues include surface and groundwater contamination, habitat loss, and feral animals. A 1996 study of mussels in the Sunrise River (an impaired river that feeds into the Saint Croix within the bounds of the proposed IBA) linked intensive agricultural and urban land use to degraded water quality. It is worth noting that the Sunrise has a feedlot on its banks; however, given the urbanization occurring in the area, it appears that intensive urbanization will present more of a challenge than will agricultural expansion.

Introduced animals and feral pets. Anecdotal evidence from area newspapers suggests that feral dogs and cats are an increasing problem.