Atkins-Hiles Swamp Research Natural Area

The Eagle River begins as a tiny stream in the wetlands of Atkins-Hiles Swamp RNA. Photo by M. Brzeskiewicz 2012, USDA Forest Service.

Eagle River-Florence
Atkins-Hiles Swamp RNA is one of the largest high quality complexes of open bog and conifer swamp in the state (Epstein 1986). Habitats include muskeg of sparse and stunted black spruce (Picea mariana), dense wet forest of black spruce and tamarack (Larix laricina) and open bog. Upland glacial features known as drumlins border the wetland and contain northern mesic forest with mixed forested swamps along the interface of the wetlands and drumlins.  There are also inclusions of northern poor fen with aspects of open bog, shrub swamp, and scattered small upland islands of virtually untouched hemlock, white pine, red pine, and white spruce. The swamp is home to several boreal plant and bird species rare in Wisconsin, including sparse-flowered sedge (Carex tenuiflora), swamp pink orchid (Arethusa bulbosa), boreal chickadee (Poecile hudsonicus), and gray jay (Perisoreus canadensis), and encompasses habitats known to serve as bald eagle (Haliaeetus leucocephalus) and goshawk (Accipiter gentilis) nesting sites.

Ecological Information

Physical and Climatic Conditions

Nearest weather station, with distance and direction from RNA:
Long Lake Dam (station no. 474829) is about 25 miles (40 km) northeast of the RNA.
Annual precipitation (type, seasonal distribution) :
Annual precipitation averages 32 inches (81 cm), 67% of which falls between April and September. Average seasonal snowfall is 64.6 inches (164 cm).
Maximum and minimum temperatures:
Daily summertime temperatures average 56° F; average daily maximum temperatures average 51.4° F. Average temperature in the winter is 23.1° F; average daily minimum temperatures average 27.6° F.
Elevations range from 1,650 feet (503 m) to 1,700 feet (518 m) MSL.
Geology and Soils:
The geology of the Atkins-Hiles Swamp RNA was shaped by the retreat of the Laurentide Ice Sheet. As this glacier retreated, till deposition and glacial melt-water formed an irregular landscape of hills pocked with depressions that later became lakes and wetlands. Bedrock includes igneous, metamorphic, and volcanic rock that is between 50 and 5 feet from the land surface. Geomorphologic processes include till deposition and glacial meltwater deposition. Surficial deposits include kame terraces and drumlin moraines.
Soils are very poorly drained nonacid organic soils that are found in the lowland areas along with well-drained loamy and sandy soils with a silt loam or sandy loam surface over non-calcareous gravelly sand (USDA Forest Service 2003a). Also present are moderately drained loamy soils with a silt loam or a fine sandy loam surface over a fragipan over non-calcareous loamy sand till. Nutrient status is medium to rich and moisture regime is dry-mesic to mesic.
Aquatic Features:
The Eagle River has its origins within the swamp on the north end of the complex and drains north as it winds its way through the swamp for about 2 miles (3 km). Its banks consist of alder thicket and northern sedge meadow, both with abundant wet sphagnum hummocks. An un-named creek forms in the south end of the complex and drains south into Atkins Lake outside the RNA.

Ecological Classification & Inventory

Laurentian Mixed Forest Province, Northern Highland (212X)
Brule and Paint Rivers Drumlinized Ground Moraine (Xc)
Land Type Association(s):
Iron River/Argonne Drumlins (Xc01) and Argonne Outwash Plains (Xc02)
Plant Communities:

Curtis Community Type

Kotar Habitat Types

Dominant Species initial US National Vegetation Classification
Northern dry-mesic forest PMV white pine and red pine Pinus strobus - (Pinus resinosa) - Quercus rubra Forest CEGL002480
Northern mesic forest TMC hemlock hemlock and sugar maple Tsuga canadensis - Acer saccharum - Betula alleghaniensis Forest CEGL005044
Northern mesic forest ATM red maple, sugar maple Acer saccharum - Tilia americana / Ostrya virginiana - Carpinus caroliniana Forest CEGL002062
Northern mesic forest ATD sugar maple Acer saccharum - Betula alleghaniensis - (Tilia americana) Forest CEGL002457
Northern mesic forest ATM aspen, balsam fir (Populus sp seral forest)
Northern wet-mesic forest N/A black ash, northern white cedar, and balsam fir Fraxinus nigra - Mixed Hardwoods - Conifers / Cornus sericea / Carex spp. Forest CEGL002105
Northern wet forest N/A black spruce and tamarack Picea mariana-(Larix laricina) /Ledum groenlandicum/Sphagnum spp Forest CEGL005271
Alder thicket N/A Alnus incana Alnus incana Swamp Shrubland CEGL002381
Open bog N/A Leatherleaf, Labrador tea Chamaedaphne calyculata - Ledum groenlandicum - Kalmia polifolia Bog Dwarf-shrubland CEGL005278
Northern sedge meadow N/A Blue-joint grass, spotted joe-pye weed Calamagrostis canadensis - Eupatorium maculatum Herbaceous Vegetation CEGL005174 or Carex stricta - Carex spp. Herbaceous Vegetation CEGL002258
flooded areas and ponds N/A Pondweed, Hornwort, Waterweed Potamogeton spp. - Ceratophyllum spp. Midwest Herbaceous Vegetation CEGL002282
    White water lily, bullhead lily - emergent Nymphaea odorata - Nuphar (microphyllavariegata) Herbaceous Vegetation CEGL002562

Complete Plant List

Common Shrub Species:
Hiles Swamp is dominated by Black spruce (Picea mariana) and tamarack (Larix laricina), with other ericaceous shrubs common.  Alder (Alnus incana) thickets are also common along the margin of Eagle River.
Common Herbaceous Species:
The most diverse habitat occurs in predominantly open bog habitat where sphagnum occurs in large hummocks. Several herbaceous species, such as rose pogonia (Pogonia ophioglossoides), grass pink (Calopogon tuberosus), swamp pink (Arethusa bulbosa), alpine cotton-grass (Trichophorum alpinum), sparse flowered sedge (Carex tenuiflora), and white beak rush (Rhynchospora alba) are also observed in this habitat.
Common Fauna:
Animals inhabiting the area that are commonly hunted or trapped include muskrat (Ondatra zibethicus), mink (Mustela vison), beaver (Castor canadensis), black bear (Ursus americanus), and white-tailed deer (Odocoileus virginianus). This site is embedded within an area recognized by the Wisconsin Bird Conservation Initiative as an Important Bird Area (IBA). Noteworthy among the resident avifauna are common loon (Gavia immer), wood duck (Aix sponsa), bald eagle (Haliaeetus leucocephalus), osprey (Pandion haliaetus),  American bittern (Botaurus lentiginosus), black tern (Chlidonias niger), northern harrier (Circus cyaneus), palm warbler (Setophaga palmarum) , Lincoln’s sparrow (Melospiza lincolnii) , gray jay (Perisoreus Canadensis), and boreal chickadee (Poecile hudsonicus )(Epstein 1986).
Potential Research Topics:
Topics for study include muskeg wetland ecosystems, wet-mesic forest, and rare animals. Surveys of taxa not yet recorded include amphibians, reptiles, invertebrates, bats, and other mammals.

Related link: Wisconsin State Natural Areas Program Atkins-Hiles Swamp

Related Reports and Publications

Brzeskiewicz, Marjory.  2013.  Establishment Record for Atkins-Hiles Swamp Research Natural Area.  Chequamegon-Nicolet National Forest, Eagle River District, Forest County, Wisconsin.   39 pp.

Curtis, J.T. 1959. The Vegetation of Wisconsin. University of Wisconsin Press: Madison WI.

Epstein, E. 1986. Evaluation Report: Atkins Lake. Unpublished inventory report on file in Park Falls Chequamegon-Nicolet Office.

Kotar, J.; Kovach, J.; Burger, T.  2002.  A Guide to Forest Communities and Habitats of Northern Wisconsin (2nd edition).  Madison: University of Wisconsin, Department of Forest Ecology and Management.

NGDC. National Geographic Data Committee. 2012. National Vegetation Classification Standard (NVCS). Available online: Accessed 2012.

USDA Forest Service.  2003a.  Chequamegon-Nicolet National Forest Soils (ELTP) Inventory Reports.  On file in Park Falls Headquarters.

Last Modified: August 20, 2021