Ecosystem
The landscape of Mackinac Island comprises fields, meadows, marshes, swamps, bogs, coastline, boreal forest, limestone formations and caves. Mackinac Island lies in the Alleghenian Zone, a transitional habitat zone between the Carolinian zone to the south and the Canadian zone to the north. The Hemlock-White Pine hardwood forest has a rich undergrowth of birch, elm and maple. On the Island, Mackinac State Historic Parks preserves the environment for all plant and animal life while at the same time provides an atmosphere for humans to reflect, explore and rejuvenate their spirits. Taking the time to explore the landscape while respecting the environment is an integral part of the Mackinac Island experience.

Natural Features
Mackinac Island State Park provides opportunities for visitors to experience firsthand the unique features of a northern boreal forest and witness the effects of receding glaciers. Natural landmarks such as the slowly-eroding limestone formations of Arch Rock, Devil’s Kitchen and Sugar Loaf encourage visitors to adopt a system of measuring time in hundreds of years, rather than in the hours, minutes and seconds of everyday life in the twenty-first century.

The physical structure that has become Mackinac Island today began to emerge over 15,000 years ago as the great glaciers receded. The Island rose above lake-level and the erosive action of the ancient Great Lakes against the Island’s limestone bedrock created today’s cliffs and rock formations. Salt deposits under the limestone were washed away, leaving cavern holes in the rock. Weakened by the removal of the softer minerals within its many layers of limestone sediment, much of the rock shattered and collapsed. As the water levels fell, dissolved minerals became concentrated and bound the limestone fragments together much like cement. The resulting rock is known as breccia. The brecciated limestone is seen throughout the Island and its fragile form is noticeable, as lime-loving cedar roots have penetrated cracks, forcing rocks apart, creating rockslides along the bluffs. Since the limestone is obviously fragile and breaks easily, no climbing is allowed on any limestone formation. The Mackinac Island State Park has erected barriers to protect the 15,000 year-old formations from destruction accelerated by human contact.
At this point in Mackinac’s geological history, the island is 2200 acres in size: two miles wide, three miles long and eight miles around. All natural formations listed below can be visited without charge and are within boundaries of the Mackinac Island State Park. The Mackinac Island State Park has posted signs directing visitors through the many riding, bicycling and walking trails to all natural features. All can be reached by bicycle and some are within easy walking distance of the downtown area.

Arch Rock
Rising nearly 150 feet above the water, Anishinaabe-Ojibwe tradition describes Arch Rock as the place where the Great Creator blew the breath of life into the newly created earth. According to legend, Arch Rock is also the gateway through which the Great Creator passed on his way to Sugar Loaf, his Island home. This limestone formation can be seen from M-185, high above the Island’s exterior lakeshore on the Island’s east side. To get a closer look, a wooden stairway and nature path leads from the lakeshore road up the bluff to the uppermost part of the formation. Arch Rock is also accessible from many trails in the Island’s interior. For those who prefer to see this natural wonder in a more leisurely fashion, the limestone monument is one of many featured stops on the Mackinac Island Carriage Tour.

Devil’s Kitchen
This excellent example of a limestone cavern created by the effects of erosion and cedar-root displacement of rocks can be seen from ferryboats approaching the Island west of Grand Hotel. An easy bicycle ride along M-185, Devil’s Kitchen is a popular picnic spot and resting point where travelers enjoy the view of the Mackinac Bridge and the many freighters passing through the Straits.

Sugar Loaf
The dwelling place of the legendary Great Spirit or Gitchie Manitou until the coming of the Europeans, this limestone bluff may be viewed from the ground up from the road below or by looking down from Point Lookout. A long wooden stairway nearby leads travelers up the bluff to Point Lookout. Sugar Loaf, once surrounded by the ancient Lake Algonquin, is a cone-shaped, brecciated limestone formation rising 75 feet above the forest floor. Sugar Loaf can be reached by foot trails or by bicycle and is a popular Nordic skiing destination in the winter.

Skull Cave
Below Fort Holmes on Garrison Road, Skull Cave is believed to have been the hiding place for English Fur Trader Alexander Henry during Pontiac’s Rebellion in 1763. His close friend, Ojibwe chief Minavavana sent him to hide in the cave on a bed of human bones in order to save him from death.

Mammals
The Straits of Mackinac have served as a barrier for all sorts of land mammals, although occasionally, larger mammals like coyote, wolf, deer or bear may make the three to seven mile journey over to the Island by crossing the ice bridge in the winter. The most abundant species of mammal living on the Island is the bat, the only mammal capable of flight and therefore the only mammal for which the straits pose no significant barrier. Having found a comfortable ecological niche on the Island, Mackinac’s bats eat insects and nectar from flowers, pollinate plants, disperse seeds and control insect populations. One bat is capable of eating up to 600 mosquitoes an hour and each bat usually eats for several hours every night. As the sun sets on a mid-summer night, this Mackinac Island favorite can be seen eating mosquitoes and other insects, serving as a natural form of pest control. With the limestone caves abundant throughout the island and the large supply of insects and plant life, Mackinac’s ecosystem is ideal for the bat and the bat is ideal for this ecosystem.

Wildflowers
Mackinac Island has long been admired for its natural beauty. Because of the topography, geological history, soils and climate, there are a great variety of niches supporting over six hundred species of vascular plants.

Spring finds the forest floor covered in a mixture of spring ephemerals including Large Flowered Trillium, Trout Lily, Spring Beauty, Hepatica, Violets and Yellow Lady Slippers. By summer, these give way to the Wood Lilies, Buttercups and Hawkweeds. The wetlands along the shoreline are blessed with a variety of orchids, Fringed Gentian and Jack-in-the-Pulpit. Six species of asters including Tall, Zigzag and Ohio cover the fall landscape under the dramatic show of colors given by the Maple, Birch and Elm trees of Mackinac’s boreal forest. Snow blankets the Island during the winter months when the dark greens of the Cedar, Pine and Spruce contrast with the red berries of the High Bush Cranberry and the mahogany stems of the Red Osier Dogwood.

The diversity of the plant life, rich contrast and splashes of color create a stunning backdrop for Mackinac’s wildflowers. Yet, it is the quiet announcement of seasonal change through the wildflowers that makes one appreciate the natural beauty of Mackinac Island’s living landscape.

Enjoy Mackinac’s abundance of natural beauty, but remember that state law prohibits the picking of wildflowers.

Birds
A popular migration spot, Mackinac Island is a resort habitat to many species of birds. Because birds dislike flying over cold waterways, they often "island-hop" across the Great Lakes to their summer homes in the north. Golden and Bald Eagles, Sharp Skinned, Red Tailed and Broad-Winged Hawks are especially abundant in late April and early May while the Yellow Warblers and American Redstart and the iridescent blue color flash of the Indigo Bunting flying past pleasantly startles and excites visitors during the early summer months.

Many birds prefer to roost or rest by Mackinac’s shoreline; these include Herrings, Ring Billed Gulls, Cormorants, Red-Breasted Mergansers, Great Blue Herons, Canadian Geese and Loons. During the winter months the Snowy Owl and Great Gray Owl fly south from the arctic to hunt and enjoy the "warmer" climate found on Mackinac Island.

The musical "ze-ze-zu-ze" call of the Black Throated Green Warbler can be heard as well as the puzzling and unusual call of the Veery. The Island’s most aural year-round resident, the red-crested Large Pileated Woodpecker regularly delivers its "Woody Woodpecker" call across the landscape. Other year-round residents include Black Capped Chickadees, Cardinals and Blue Jays.