Places We Protect

McMahon Lake Preserve


Grasses growing out of the water onthe shore of a lake at McMahon Lake Preserve in Michigan's Upper Peninsula.
McMahon Lake Preserve The 4,084-acre McMahon Lake Preserve lies within the watershed of the Two-Hearted River. © Jason Whalen/Big Foot Media

Due to its remote location and swampy nature, the area has avoided development—so visiting the preserve is like traveling back in time.



This area was immortalized in Ernest Hemingway’s story “Big Two-Hearted River,” a tale of a man trying to find inner peace in the wilderness after he gets back from World War I. Hemingway himself spent many summers in northern Michigan and wrote this story based on his own memories of the area.

The 4,084-acre McMahon Lake Preserve, located in Luce County, lies within the watershed of the Two-Hearted River, a state-designated Natural River. This area has largely avoided logging and development due to its remote location and swampy nature. As a result, traveling through the preserve is like traveling back through time.



Pets are not permitted.


Local residents include the pine marten, moose, otter, pileated woodpecker, sandhill crane, northern harrier, bear, wolf, loon, coyote, ruffed grouse, gray jay, sedge wren and northern Parula warbler.


4,084 acres

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Exploring the Preserve

The activities below will help you explore the preserve and enhance your connection with nature—from the comfort of your home or while onsite.

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    Audio Tour

    Our guided audio tour includes stories, fun facts, historical notes, and natural sounds to help deepen your connection to the McMahon Lake Preserve. You can access the tour from the comfort of your home or onsite as you hike. Learn More

  • A person crouches down to examine green plant life while on a hike at Nan Weston Nature Preserve in Michigan.


    Help our scientists and restoration managers keep track of the species in our nature preserves by using iNaturalist. You can record your observations, help others identify species and view other users' identifications. Learn More

  • More Ways to Explore

    We offer a variety of ways to explore including geocaching, webinars, events and volunteer opportunities. You can even request a permit to use TNC lands for scientific research! Learn More

McMahon Lake Preserve (3:08) Due to its remote location and swampy nature, the area has avoided development—so visiting McMahon Lake Preserve is like traveling back in time.

Plan Your Visit

Frequently Asked Questions

  • This preserve is open year round. Early-May and late-July through October are the best times to visit this preserve to take advantage of Upper Michigan’s beauty while avoiding biting insects.

  • Come prepared with head netting and insect repellant, since the black flies and mosquitoes are abundant. We also strongly recommend wearing ankle-high boots because portions of the strangmoor are very wet.

  • For the safety of both the habitats at this preserve and visiting guests, we ask that you please follow the rules listed below.

    • No motorized and non-motorized vehicles
    • No pets
    • No hunting or trapping without a TNC-issued permit
    • No removal of plants or animals (alive or dead)
    • No removal of rocks, water or other non-organic materials
    • No camping, bonfires, fireworks or other fires
    • No littering
  • The Nature Conservancy allows hunting for white-tail deer on this preserve to reduce threats too many deer pose to our conservation targets and to ensure that the preserve does not become a “refuge” for deer during the hunting season.

    In order to be eligible to hunt at this preserve, hunters are required to receive a permit from TNC, follow TNC hunting program rules and comply with all local, state and federal laws and ordinances governing hunting activities, including obtaining all required government licenses or permits. For more information, please visit our Deer Hunting in Michigan page.

  • Have questions about the preserve? Contact us at

A beaver lodge in the center of McMahon Lake.
McMahon Lake Preserve A beaver has built an impressive lodge in the middle of McMahon Lake in Michigan's Upper Peninsula. © Fauna Creative


In 1993, an anonymous donor contributed the funds for this purchase in memory of former TNC board member and Matthaei Botanical Garden director, William S. Benninghoff. This portion of the preserve was dedicated to Dr. Benninghoff, who was instrumental in helping the Michigan Chapter identify and protect some of the most critical natural habitat in the state. Other significant gifts helping to make up this site included a 360-acre donation from The Escanaba Paper Company and a 760-acre donation from William Malpass.

Keep Exploring

From shifting sand dunes to granite bald mountains, explore our preserves and reserves spread across the state of Michigan.

Find More Places We Protect

The Nature Conservancy owns nearly 1,500 preserves covering more than 2.5 million acres across all 50 states. These lands protect wildlife and natural systems, serve as living laboratories for innovative science and connect people to the natural world.

See the Complete Map

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