Grand River Fen Preserve

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

Grand River Fen Preserve contains the second largest high-quality occurrence of cinquefoil-sedge fen in the North Central Tillplain Ecoregion. This 453-acre complex of high quality wetland communities also includes southern swamp and southern shrub-carr. This makes it critical habitat for special insects, including the blazing star borer, tamarack tree cricket, pine tree cricket, regal fern borer, angular spittlebug and red-legged spittlebug. One globally-rare plant, the bog bluegrass, is also found here, as well as a very high diversity of flowering plants, sedges, and grasses.

Access to this preserve is limited to field trips and volunteer workdays. Please email michiganvolunteer@tnc.org if you are interested in participating or visit our volunteer webpage.

The Nature Conservancy allows hunting for white-tail deer on this preserve to reduce an unnaturally high deer population in the area and reduce threats too many deer pose to our conservation targets. All hunters are required to receive a permit from the Conservancy as well as a Michigan deer hunting license. Additionally, hunters must report any deer taken from the preserve.

Why the Conservancy Selected This Site
Three separate areas of high-quality prairie fen are the heart of this site. These are renowned among lepidopterists 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. While progress should never come to a halt, there are some places it should never come at all like headwater streams, wetland complexes, and rare Great Lakes marshes.

What the Conservancy Has Done/Is Doing
The Nature Conservancy has set forth multiple conservation targets and ecological objectives for the Grand River Fen Preserve. Grand River Fen is one of our most active restoration and management sites.

Conservation Targets

  • The complex of high quality wetland communities, including prairie fen, southern swamp, and southern shrub-carr.
  • Populations of globally-rare insects and plants, including the tamarack tree cricket, the blazing star borer, the pine tree cricket, the silphium borer moth, the angular spittlebug, the Poweshiek skipperling, and bog bluegrass.
  • Populations of other rare animals, such as the regal fern borer and red-legged spittlebug.

Ecological Objectives

  • Protect the mosaic of wetland and upland ecosystems and key ecological processes, especially the cycle of groundwater recharge and discharge that maintains the prairie fens and associated rare animals and plants.
  • Locate, protect, maintain, and enhance the populations of globally rare insects.
  •  Use controlled burns and invasive species management in the prairie fens and dry prairies to improve rare insect populations.
  • Evaluate restoration of degraded dry prairie sites and other formerly open uplands.