Places We Protect

Gray-Hart Preserve


Gray-Hart Preserve
Blooming blazing star Gray-Hart Preserve © Dale Maxson/TNC

Gray-Hart Preserve protects one of the state’s largest calcareous fens and showcases many of the brilliant wildflowers native to Iowa’s wet prairies and fens.



Iowa’s rarest type of wetland, fens are a special type of wetland that depend on spring flow, instead of just surface water, to constantly saturate the soil. This perpetual saturation limits decomposition in the soil, so thick, buoyant muck or peat soil can accumulate over thousands of years. The water at this fen tends to be alkaline and calcium-rich and supports specialized “calciphile” plants like grass-of-Parnassus and sterile sedge.

Gray-Hart Preserve is one of the largest fen wetlands in the state and hosts a multitude of rare fen plants. TNC was able to protect this property due, in part, to the generous support of Marilyn Mihall, who named the preserve in honor of her parents.

Shortly after establishing Gray-Hart Preserve, TNC collaborated with Fayette County Conservation Board to seed an access lane to provide public access. More recently, the Anna Beal Intern Crew has worked to remove encroaching shrubs and trees, as well as remove old barbed wire fence that bisected the fen.




14.5 acres

Explore our work in this region

What to See: Plants

Grass-of-Parnassus, fen violet, hairy valerian, cottongrass, shooting star, prairie smoke, blazing star, marsh marigold, meadowsweet and many other wet prairie and fen plants are found at this site.

What to See: Animals

There is not a complete survey of the animals located on this preserve.

Visitation Guidelines

Please download our preserve visitation guidelines here.

“Becky’s Fen,” which is privately owned, lies adjacent to the east of Gray-Hart Preserve. When visiting Gray-Hart Preserve, please be respectful of private property and stay within the boundaries of the preserve.

Support Our Work at Gray-Hart Preserve