The Nature Conservancy in Michigan - Mary Macdonald Preserve at Horseshoe Harbor

Mary Macdonald Preserve at Horseshoe Harbor

Waves break across Michigan's most northern coastline

Enjoy Mary Macdonald's gift with your friends and family
© TNC Archives

Why You Should Visit
At the northernmost tip of Michigan’s Upper Peninsula, stunted shrubs and trees cling to ancient bedrock directly in the path of Lake Superior’s fierce winds. The 1,433 acre Mary Macdonald Preserve at Horseshoe Harbor is the largest and highest quality mainland preserve for bedrock beach and bedrock glade communities in Michigan. The rock ridges that define the shoreline are wave-eroded edges of sedimentary conglomerate rock uplifted some 600 million years ago. They now create a barrier between the pounding wind and waves of Lake Superior and the woodlands behind them, protecting and allowing the emergence of slower growth plant species.

Only the hardiest plants can withstand constant exposure to the lake’s winds and waves. The bedrock beach mostly supports lichens, which dominate this rare ecosystem. In the damp depressions between the rocks, a variety of shrubs, herbs and sedges grow.

Just inland from the bedrock beach, a boreal forest thrives in the cool, moist climate. Balsam fir, white cedar, white spruce, and white birch shelter species such as the black bear, snowshoe hare, peregrine falcon, ruffed grouse, golden-crowned kinglet, black-throated green warbler and yellow-rumped warbler.

Location
Keweenaw County, Upper Peninsula

Hours
Open year-round, dawn to dusk

Conditions
Late summer and early fall are the best times to visit this preserve to fully enjoy the beauty of the Keweenaw Peninsula without the irritation of the biting insects that come out in the early summer. Hiking boots are recommended for walking the trails and shoreline of this preserve. If you want to visit during the early summer months bring insect repellant to protect against biting insects.

How to Prepare for Your Visit
Please see "Preserve Visitation Guidelines"

Directions
From Copper Harbor, Michigan:

From the intersection of M-26 and US-41 in Copper Harbor, take US-41 2.5 miles east until the pavement ends.
Continue east on the dirt road 0.89 miles.
There is a narrow two-track trail heading left (north). (If you don't have a 4 wheel drive or have a car with very low clearance, you may want to park here and walk the 2 miles to the beach). Follow the two track 1.2 miles.
Park on the right (south) side of the road and walk east to Lake Superior. There is a sign at the head of the trail.

What to See: Plants

Alpine Bistwort: This relative of the smartweed family is usually found in rock crevices in the bedrock shores of Lake Superior and is partial to neither sun nor shade. Primarily, it requires the protection of shoreline habitat and the perpetuation of natural disturbance such as winter ice, storms, and wind.
Rayless Mountain Ragwort: This member of the Aster family is also native to California. It enjoys a variety of rocky habitats including: moist woods of conifers, rocky lake shores, and cliffs.
Bedrock Glade: Characterized by droughty, thin soil and bedrock outcrops covered by sparse vegetation, bedrock glades occur on the summits of rocky hills and ridges and on south to west faces of higher mountains. Scattered clumps of often stunted trees, patches of shrubby growth, scattered herbs, and lichens are the main types of plant life seen on bedrock glades.

What to See: Animals

Black Bear: As opportunistic feeders, Michigan's only bear species take advantage of many seasonally available foods. In the spring, they enjoy new green vegetation after leaving their dens. Summer foods include insects and wild berries. Nuts and acorns are the best fall foods when preparing for their winter's sleep. Adult males weigh between 150-400 pounds and measure about three feet high when on all four feet and about five feet when standing upright.
Peregrine Falcon: These falcons require large areas of open air for hunting, and subsequently, are not found in heavily forested. Their diet includes a wide variety of small birds, including pigeons, seabirds, shorebirds and songbirds. Peregrines hunt by diving at their prey from far above and catching them in mid-flight. During these incredible dives, called "stoops", the birds can reach speeds of 180 miles per hour.

Why the Conservancy Selected This Site
Horseshoe Harbor is the largest and highest quality preserve for bedrock beach and bedrock glade communities in Michigan. Our protection efforts in this wondrous place began in 1982, when Conservancy member and Copper Harbor resident Mary Macdonald donated the original 535 acres to create this preserve and made an additional gift that allowed the Conservancy to purchase another 334 acres. In all, 11 threatened or rare species have been recorded at the preserve.

What the Conservancy Has Done/Is Doing
We have added a bit of land at a time, nearly doubling the preserve's size in the last 16 years.

Sources for information include MNFI and MDNR.