Places We Protect

Grand River Fen Preserve


A river runs through a fen filled with wildflowers and other plant life.
Stream at Grand River Fen Preserve Grand River Fen Preserve is home to the longest river in the state of Michigan, the Grand River. © Jason Whalen

The fen is a critical habitat for special insects and a globally-rare plant, the bog bluegrass.



See the start of Michigan's longest river as you walk through the beautiful wooded wetlands of the Grand River Fen Preserve. Native butterflies occur in very high abundance at the fen. This site has long been known by lepidopterists for its diversity of these beautiful insects. Species like the Baltimore checkerspot may follow you around, seeking the salt in your sweat.

Several species of the showy plant, blazing star, occur in the fen. With a narrow spike of bright purple flowers, they somewhat resemble the invasive plant, purple loosestrife, but these are all native.



Pets are not permitted.


Hiking, birdwatching, butterfly-watching


627 acres

Explore our work in Michigan

Exploring the Preserve

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

  • 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 land for scientific research! Learn More

Grand River Fen Preserve (3:15) See the start of Michigan’s longest river as it begins nestled in a protected area that provides habitat for fluttering butterflies and dazzling wildflowers.

Plan Your Visit

Frequently Asked Questions

  • This preserve is open year round. 

  • Plan for the weather! Hiking boots are recommended, as well as long clothing or insect repellent in the summer.

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

    • No rock climbing and rappelling
    • No motorized and non-motorized vehicles
    • No building of new trails
    • No pets
    • No hunting or trapping without a Conservancy-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 firewood collecting
    • No littering
  • The Nature Conservancy allows bow and firearm 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 ground view of the water surrounded by green plants.
Flora and Fauna The fens and associated swamp and upland forest communities harbor a regionally significant and diverse fauna and flora. © Jason Whalen/Big Foot Media


Three separate areas of high-quality prairie fen are the heart of this site. These are renowned for the diversity of butterflies and moths, including four globally-rare species. The wetlands occupy a glacial outwash channel that forms a portion of the headwaters of the Grand River.

The fens and associated swamp and upland forest communities harbor a regionally significant and diverse fauna and flora including seven globally-rare and eight state-rare species.

One globally-rare plant, the bog bluegrass, is also found here, as well as a very high diversity of flowering plants, sedges and grasses.

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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