Cowan Lake State Park offers a peaceful setting replete with scenic inlets laden with the American Lotus water lily. Swimming, fishing, sailing and canoeing are popular on the lake. Meandering trails through mature woodlands compliment the natural features of this scenic park.

It has been said that Ohio's history can be found written in the rocks. By studying the bedrock layers in Ohio, we know that ancient seas, marshes or swamps covered all or portions of the state at times over the past 500 million years. Sediment deposited by those ancient waters solidified into rock and eventually uplifted forming dry land. Animals and plants were embedded in the sediment, and today, these fossils reveal the different life forms that existed in Ohio's past.

Cowan Lake lies near the Cincinnati Arch, an uplifting of bedrock that occurred during the Appalachian Mountains' building process. The erosion of this arch in the Cowan region exposes fossil-rich limestone. The limestone near Cowan and other parts of the exposed arch are some of the most famous fossil hunting fields in the world. (Collection of fossils requires a permit from the Chief)

A fine stand of beech-maple forest can be found around the lake at Cowan. These woodlands contain beautiful wildflowers including bloodroot, wild ginger, springbeauties and trillium. The woods, fields and lake provide habitat for a variety of animals. Ring-neck pheasant, ducks,geese and herons are found here. Songbirds such as eastern bluebirds, catbirds, house wrens and many others inhabit the fields and bushy areas of the park. Mammals include white-tailed deer, raccoon, opossum, woodchuck, skunk and others.

American Lotus, a brilliant water lily, is abundant in the lake's shallow areas. It is unusual to find such a large colony of lotus on an inland lake. The plant's leaves grow up to two feet in diameter supporting large yellow flowers.

The Cowan Lake region was once a stronghold of the Miami and Shawnee Indians. After their defeat at the hands of General Anthony Wayne at the Battle of Fallen Timbers, the Indian threat subsided and settlement began here. In 1797, the first settler in the area, William Smalley, began clearing land for his home along the river which was later dammed to form Cowan Lake. Smalley had been captured by the Indians when he was a small child and was forced to live with them until he was twenty years old. He later fought in General Wayne's army, was recaptured, but luckily escaped with his life.

Cowan Creek was named for the area's first surveyor,John Cowan. A dam was completed across Cowan Creek in 1950, and in 1968, Cowan Lake was dedicated as a state park.

The campground has 254 campsites. Of that total, 237 campsites have electricity suitable for tents or trailers and 17 sites are non-electric. Four sites are wheelchair accessible. The campground is equipped with a showerhouse, flushtoilets, laundry facilities, dump station, camper's beach and a boat launch ramp. A commissary is equipped with snacks and camping items. Pet camping is offered on designated sites.

There are 27 family cottages situated in a wooded setting along the lake. Each cottage is heated and air-conditioned, has two bedrooms, bath, living area with a sofa bed, complete kitchen, dining area and screened porch. Linens, towels, cooking and eating utensils are provided. Two premium cottages have gas fireplaces. The fireplaces are not in operation from Memorial Day to Labor Day.

A public beach is located on the south lake shore. A bathhouse, showers and a snack bar are provided.

Boats with a ten horsepower limit are permitted on Cowan Lake. The South Shore Marina concession offers boat, canoe and motor rental as well as fishing and picnic supplies. Launch ramps, fuel and dock rentals are also available. Sailing is very popular on the lake.