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U.S. Forest Service

Eastern Region Viewing Area


View of Fall River Patterned Fen from  the ground. View of Fall River Patterned Fen from the ground. Photo by Jack Greenlee, Superior National Forest.

Aerial view of the fen. Aerial view showing the strings and flarks, in a north-south orientation, of the Fall River Patterned Fen.

Drosera rotundifolia. Round-leaved sundew (Drosera rotundifolia). Photo by Erin Heep, Superior National Forest.

Arethusa bulbosa. Dragon’s-mouth orchid (Arethusa bulbosa). Photo by Erin Heep, Superior National Forest.

Menyanthes trifoliata. Bogbean (Menyanthes trifoliata). Photo by Erin Heep, Superior National Forest.

Fall River Patterned Fen

Forest: Superior National Forest

District: Gunflint Ranger District

Description: The Fall River Patterned Fen is unique to northeastern Minnesota because it is the only patterned fen in the far northeastern part of the state. Nevertheless, what exactly is a patterned fen? First, it is helpful to understand the basic difference between two types of peatlands: fens and bogs. The differences can essentially be attributed to how water enters the peatland. Fens are peatlands that receive nutrient-rich water from adjacent uplands. Although nutrient levels vary, fens are always more nutrient-rich than bogs and less acidic than bogs (pH greater than 5.7). Bog peatland surfaces are slightly convex and raised, so the mineral-rich water from adjacent uplands gets diverted around the peatland. Bogs receive water and nutrients only from rainfall and snowmelt. Bogs are relatively nutrient poor and acidic (pH less than 4.2).

Patterned fens are the result of complex hydrological processes. A patterned fen, in a profile view, is concave to flat, so runoff is channeled across the peat surface. A distinctive pattern of miniature ridges (strings) and pools (flarks) is formed and arranged perpendicular to the slope. The pattern is best seen from the air, but is observable on the ground. In the Fall River Patterned Fen, the strings and flarks patterning is most visible on the ground toward the middle. A keen observer will also notice that some plants occur only on strings and others only in flarks. In addition to having higher species diversity, fens can be distinguished from bogs by the presence of fen indicators species. Some examples of fen indicators that you will not see in bogs are bogbean, white beakrush, mud sedge, and intermediate-leaved sundew. The Fall River Patterned Fen is on the mineral-poor end of the spectrum, so many bog species are present, and some of the species found in more mineral-rich fens are absent.

Viewing Information: The best time to see the showy and colorful dragon’s-mouth orchid (Arethusa bulbosa) is in June, whereas July and August are the best months to search for the uncommon club-spur orchid (Plathanthera clavellata). Amongst scattered, stunted black spruce (Picea mariana), tamarack (Larix laricina), and a carpet of Sphagnum are many typical peatland species. These species include leatherleaf (Chamaedaphne calyculata), bog laurel (Kalmia polifolia), bog rosemary (Andromeda glaucophylla), small bog cranberry (Vaccinium oxycoccos), Labrador tea (Ledum groenlandicum), podgrass (Scheuchzeria paulustris), round-leaved and intermediate-leaved sundews (Drosera rotundifolia and D. intermdia), three-leaf Solomon’s-seal (Maianthemum trifolium), pitcher plant (Sarracenia purpurea), cottongrasses (Eriophorum spp.), bogbean (Menyanthes trifoliata), white beakrush (Rhynchospora alba), mud sedge (Carex limosa), few-flowered sedge (C. paucifolia), and poor sedge (C. magellanica).

Safety First: Always bring drinking water and a snack. Expect plenty of biting insects in June, July, and August. Rubber boots are recommended. The snowmobile/hiking trail that accesses the site is mowed during the summer months. However, there is no trail between the fen and the snowmobile/hiking trail, and there is no boardwalk in the fen, so be prepared with a map or air photo and compass, or a GPS unit (and extra batteries). There are also no signs along the snowmobile/hiking trail to direct you to the fen. It is not particularly difficult or strenuous, but it is important to be prepared.

Directions: Grand Marais is 115 miles northeast of Duluth, Minnesota on State Highway 61. From Grand Marais, go approximately 2 miles north on the Gunflint Trail (County 12) to the Old Ski Hill Road (County 64) on the left (west). Proceed 1 mile down the Old Ski Hill Road, and look for a parking lot just off the road where a snowmobile/hiking trail crosses. The trail is gated on both sides of the road, and, since the Superior Hiking Trail (SHT) shares the snowmobile trail here; you might observe a small SHT sign near the trail. Hike on the trail that heads west (opposite the parking area). Depart the snowmobile/hiking trail at any point between 0.75-1 miles from the parking lot. Make your way south through a lowland black spruce forest (less than 0.25 mile) to the open fen.

Ownership and Management: U.S. Forest Service, Superior National Forest, Gunflint Ranger District.

Closest Town: Grand Marais, Minnesota.