Places We Protect

Grass Bay Preserve


An orange and purple sunset over water.
Grass Bay Preserve Looking out along the shoreline of Grass Bay Preserve, Michigan. © Jason Whalen/Big Foot Media

Grass Bay Preserve is a paradise for wildflowers and neotropical migrating birds along two miles of Lake Huron shoreline.



Three species of wildflowers are found nowhere on Earth but along the Great Lakes and they all thrive at Grass Bay—the diminutive dwarf lake iris (blooming in purple or white), Pitcher’s thistle and Houghton’s goldenrod. The songs of such neotropical migrants as the black-throated blue warbler and the prairie warbler can be heard throughout the diverse landscape of shoreline, open dunes, interdunal wetlands, coniferous swamps and forests. It is home to 12 of Michigan’s 13 coniferous species and over 300 plant species.


The Nature Conservancy first became aware of Grass Bay’s amazingly lush and diverse flora in 1978. When the original 80-acre parcel went on the market in 1979, TNC secured an option to purchase it. Because the Federated Garden Clubs of Michigan treasured this site and also wanted to see it protected, they launched a very successful multi-year campaign to raise money to assist TNC in purchasing the original parcel, plus approximately 100 more acres soon after.




Wildflowers, migrating birds, Lake Huron shoreline, open dunes, interdunal wetlands, coniferous swamps and forests.


834 acres

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What to Do and See

Download a Preserve Brochure

Please note, there is no on-site parking lot available at this location. Visitors may park along the roadside using caution. The trailhead is located in Benton Township, MI 49721 approximately .2 miles past Thirsty’s Bar and Grill on the left (north side) of US-23, marked with green metal posts (coordinates: 45.649833, -84.372056). A new parking area is being considered for this site for 2022-2023. Learn more about our plans to enhance visitor experiences across our preserves

Spring and fall are the two best seasons to visit this preserve, as you'll likely be able to spot migratory birds and wildflowers. Many species can be observed in the mix of habitats found at Grass Bay. Be sure to wear a hat and sunscreen as well as sturdy walking shoes or boots, and bug repellent. Expect rugged, narrow and uneven terrain on natural pathways. 

Special note: 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 the habitat. All hunters are required to receive a permit from TNC as well as a Michigan deer hunting license. Additionally, hunters must report any deer taken from the preserve. 

Permitted Activities:

  • Foot access for hiking, snowshoeing, bird watching, etc.
  • Educational studies, photography, journaling 
  • Hunting (with TNC-issued permit and Michigan hunting license) 

Prohibited Activities:

  • No motorized and non-motorized vehicles, including but not limited to automobiles, off-road vehicles (ORVs), all-terrain vehicles (ATVs), motorcycles, snowmobiles, amphibious vehicles, and bicycles.
  • No pets
  • No geocaching
  • No removal of trees, plants or animals (alive or dead)
  • No removal of rocks, water or other non-organic materials
  • No camping, bonfires, fireworks or other fires
  • Swimming at this site is particularly dangerous and therefore not allowed


Spotlight on Nature: Grass Bay Preserve is a paradise for wildflowers found only along the Great Lakes.