In early spring, the natural area hosts one of the park system's most spectacular wildflower shows as blue-eyed Marys, celandine poppies, bluebells, trilliums and violets burst into bloom. In contrast, on the hills above are limestone glades and savannas, which are remnants of the area's earlier, presettlement appearance. These open forests and sparse grasslands are scattered throughout the park's uplands and along most of the trails. The trees are often quite small, even though they may be more than 200 years old. Many of the flowering species found on these glades, such as Fremont's leather flower, the delicate blue-violet nemastylis and a rare primrose, are found in few other parks.
Animal life is unusual, too.
The eastern collared lizard is a favorite of visitors as it folds its front legs up against its chest like a miniature dinosaur and sails along on its hind legs, jumping over rocks. Another notable natural feature of the park are the towering dolomite bluffs overlooking the Big River, a popular floating and canoeing waterway. Below the bluffs, anglers enjoy catching bass, catfish, bluegill and carp. Swimmers and sunbathers have a choice between a natural gravel bar in the river or an Olympic-size swimming pool. A picnic gazebo located at the scenic overlook provides a majestic view of the Big River and surrounding area.