I'm sorry, but there is an error in your request. Nathan Forrest State Park is actually located in Tennessee, not Illinois. Here is a summary of the park:

Nathan Forrest State Park is a 2,587-acre park located in Benton County, Tennessee. The park offers an array of recreational activities, including camping, fishing, boating, hiking, biking, and swimming.

One of the park's main attractions is its 690-acre man-made Lake Placid, which offers excellent fishing opportunities for bass, crappie, and catfish. Additionally, the park features several hiking trails, including the 1.5-mile Nature Trail, the 1.2-mile Pine Trail, and the 0.75-mile Lakeshore Trail.

For history buffs, the park features a Civil War cemetery and a monument dedicated to the park's namesake, Nathan Bedford Forrest, a Confederate general who was born in the area.

Visitors can also enjoy the park's picnic areas, playgrounds, and volleyball courts.

The best time to visit Nathan Forrest State Park is in the spring or fall, when the temperatures are moderate and the leaves are changing colors. However, summer is also a popular time to visit due to the lake's recreational opportunities.

Overall, Nathan Forrest State Park offers a beautiful natural setting with plenty of outdoor activities for visitors to enjoy.