Twin Lakes Bog Research Natural Area


This RNA consists primarily of an even-aged stand of tamarack (Larix laricina). The most unique features of this RNA site are three small, deep softwater seepage lakes, an undisturbed conifer swamp, and its associated ericad bog. The understory flora is notable for the large number of moccasin flower (Cypripedium acaule).

Ecological Information

Physical and Climatic Conditions

Nearest weather station, with distance and direction from RNA:
The nearest weather station is in Medford, Wisconsin, located approximately 11 miles (17.6 km) to the southeast.
Annual precipitation (type, seasonal distribution) :
Mean annual precipitation is 33 inches (82.5 cm). Average annual snowfall is 60 inches (150 cm).
Maximum and minimum temperatures:
The mean annual temperature is 41.2ºF. The maximum summer temperature is 104ºF. and winter minimum temperature -45ºF.
Elevation ranges from 1450 feet (435 m) to 1470 feet (441m).
Geology and Soils:
Precambian granite bedrock underlies this area. The landscape is young in geologic age and characterized by a deranged type of drainage pattern. The predominant soil series is the Sarona Series, which is well-drained soil formed in loamy sand and sandy loam glacial till on moraines.
Aquatic Features:
Three small, deep, softwater seepage lakes (2.3 acres), an undisturbed conifer swamp, and an associated ericad bog are present. The RNA drains into South Twin Lake.

Ecological Classification & Inventory

Southern Superior Uplands (212J)
Perkinstown End Moraine (212Jf)

SAF Cover Types (list acres):

Kuchler Types (list acres):

25 Sugar maple-beech-yellow birch (8) 85 Conifer Bog (25)
38 Tamarack (25) 99 Northern hardwoods-Spruce forest (8)

Complete Plant List

Common Shrub Species:
Labrador tea (Ledum groenlandicum), swamp laurel (Kalmia polifolia), leatherleaf (Chamaedaphne calyculata), common mountain holly (Nemopanthus mucronata), winterberry (Ilex verticillata).
Common Herbaceous Species:
Sedge sp. (Carex disperma, C. lasiocarpa, C. limosa), twinflower (Linnaea borealis), cinnamon fern (Osmunda cinnamomea), bunchberry (Cornus canadensis), buckbean (Menyanthes trifoliata), bladderwort (Utricularia sp.), sundew (Drosera intermeida, Drosera rotundifolia), pitcher plant (Sarracenia purpurea), tall northern bog-orchid (Habenaria hyperborea), moccasin flower (Cypripedium acaula), yellow water lily (Nuphar variegata).
Common Bird Species:
Solitary vireo (Vireo solitarius), hermit thrush (Catharus guttatus), black-and-white warbler (Mniotilta varia), white-throated sparrow (Zonothrichia albicollis).

Related link: Wisconsin State Natural Areas Program Twin Lakes Bog

Related Reports and Publications

Herman, Ron. 1988. Establishment Record for Twin Lakes Bog Research Natural Area within the Chequamegon National Forest, Taylor County, Wisconsin. 23 pp.

Last Modified: August 20, 2021