The Dunes of West Michigan

Along the eastern shore of Lake Michigan lies a continuous swathe of ancient sand dunes. Shaped and reshaped by wind, weather and moisture, the undulating dunes between Little Point Sable to the south and Big Point Sable to the north mark the furthermost western points of land on Michigan’s Lower Peninsula. Throughout the post-glacial era this landscape—with its mix of high dunes, balds and blowouts, deep swales, and forested back dunes—has evolved in response to natural forces of climate as well as human intervention. While many visitors are familiar with the dynamic process of shifting sands and the “rolling” dunes that line the Lake Michigan shore, few are familiar with the evolution of the larger dune environment that has influenced the ecology and history of West Michigan.   

The Pentwater Conservation area provides a close look at the slowly evolving process of dune creation on the inland reaches of what the Michigan Natural Features Inventory classifies as a characteristic “dune and swale complex.” Here more than a mile from the lake, the sandy soil deposited over time has mixed with windblown leaves, decaying bark and needles, and fallen branches to form an acidic soil cover that provides a sustainable growing medium for white pines, which are adaptable to fluctuating levels of moisture, and a host of associated forbs and shrubs. Wintergreen, trailing arbutus, black huckleberry, and low-growing blueberry abound in the shade of the treed canopy providing a habitat attractive to a variety of insects, woodpeckers, migratory birds, amphibians, and small mammals. Particularly distinctive are the moss, fungi and lichens that cling to both living and decaying wood and form a rich carpet at the base of trees and in the shallow depressions that capture moisture from seasonal storms. 

Predominant strong winds from the southwest and northwest have imprinted a repetitive parabolic patterning on the land as the dry (xeric) and relatively barren lakefront dunes give way to successive tiers of back dunes and ridges with intervening swales and mesic growing conditions. Through time the back dunes have gradually merged to form a series of forested ridges. As wind-blown organic matter collects on the gradual windward slopes of the back dunes, mesic conditions favorable for a wider range of plants and trees emerge. 

These forested dunes of Lake Michigan today provide a natural barrier – one that offers the dune landscape protection from the natural forces of wind and weather from the west and the pressures of human activity from the east. 

You can help the PCO protect this fragile environment. We ask visitors to keep on the trail, and refrain from disturbing any trailside vegetation or climbing on the slopes on the edges of the trail. Pets are not allowed on the trail or in the nature preserve.