The park bluffs command the first attention of the visitor. The four prominent hollows one views are ravines cut into an elevated plain. About 200 million years ago, what is now Illinois, was lifted from the sea for the last time and the age of the lizards followed. As the giant dinosaurs flourished, this region was the scene of earth movements that resulted in a dislocation of the rocks, producing the Lincoln Fold.
Thus it happens that one is now in the eastern end of the Lincoln Hills which extend 30 miles from Lincoln County, Missouri, into Jersey County, Illinois. To the north the bedrock was uplifted 50 feet per mile, and pulled down steeply hundreds of feet to the south. At Pere Marquette State Park the Illinois River has cut a section through these folded beds. Rocks dipping at 45 degrees are plainly visible at two places along the foot trail and bridle path to Twin Springs. Here one can climb the Lincoln Fold just to the north of the Nature Museum on the foot trail to Goat Cliff.
FOSSILS REFLECT HISTORY
The life of those times, preserved as fossils, reveal the development of the higher invertebrates, then the fishes, and finally land animals and plants. At the foot of McAdams Peak, Twin Springs flows from Ordovician-Silurian rocks, deposited in the sea 350 million years ago. All the ridges are mantled with loess (pronounced “less”), wind blown dust laid down a million years ago at the time of the Great Ice Age. The vertical banks of yellow clay seen along the road to the upper areas are composed of this material, capped by the black topsoil that supports the present forest.
More than 60 species of trees have been listed; Pecans, Red Cedars and Butternuts being notable. Spring comes with the flowering of the Shadbush; Redbud and Wild Plum are succeeded by the even more lovely Dogwood. Flowers abound, and later berries light up dark places, and mosses, ferns and lichens, form an agreeable ensemble. Mushrooms are conspicuous for their number. With autumn the woods are a never-to-be-forgotten blaze of color.
MANY ANIMALS HERE
The varied habitats support a vast and unusual assemblage of animals. Fish, as only the Illinois valley knows them, fatten in the waterways. All four species of lizards known in Illinois scamper over the lichen-covered rocks. The whole series of fur-bearing animals now left in Illinois are here to be seen. It may be that in these endless acres that a Whitetail Deer or Wildcat still lingers, certainly an occasional Coyote and the re-introduced Beaver.
Hundreds of species of birds, especially in time of migration, can be seen and studied to great advantage. The Mockingbird sings all day; the woods ring with the calls of Thrush, Wren and Towhee, and the fields echo with Meadow Lark and native sparrow songs. Vireo, Oriole and Cardinal are everywhere. Hawks, Vultures, and the symbol of the United States, the Bald Eagle, soar over McAdams Peak. Osprey, Herons, Bitterns, Cormorants, Grebes and Loons are about the water. Even Pelicans and Ibises appear in the summer. Especially in migration, Ducks, Geese, Gulls, and all the tribe of Sandpiper, Plover, Snipe, Cranes and Swans on very rare occasions. All these and many others frequent this part of the Mississippi Flyway, the migratory highway of central North America. This was the Indian’s happy hunting ground, now an American paradise in perpetuity.
For further information concerning Illinois State Parks and Memorials write to the DIVISION OF PARKS AND MEMORIALS, 100 State Office Building, Springfield, 62706.
Our numerous State Parks and Memorials are of easy access from every part of the state. Lodges, cabins, and dining rooms are important features of Illinois Beach, Starved Rock, Pere Marquette, White Pines Forest, and Giant City State Parks. Reservations for lodging should be made with lodge managers.
All State Parks are open the year round, except when weather condition necessitates the closing of park roads during the freezing and thawing periods. Then access to park facilities is by foot traffic only. All State Memorials open the year round except Thanksgiving, Christmas, and New Years.
(Printed by authority of the State of Illinois)
Issued by
DEPARTMENT OF CONSERVATION
Division of Parks and Memorials
50M—7-67
