Recreational activities at Illinois Beach State Park include boating, swimming, hiking, bicycling, camping, bird watching, and picnicking. Known primarily for the beach, Illinois Beach State Park also includes dune areas, wetlands, prairie, and black oak savanna. The area at the far southern end of the park is a designated nature preserve, which was named a National Natural Landmark in 1980.
The park was gradually created starting in 1948 when the state acquired the first parcels. The northern unit, acquired between 1971 and 1982, was previously an Illinois National Guard training facility known as Camp Logan, Illinois. During the American Civil War, Camp Logan was a Union prisoner of war camp.
The entry to the beach is usually from a parking area on its north side: north of this carpark is usually the most crowded area in the summer time. South, the beach is less crowded and a mile of shoreline extends to an inlet into a wetland. Depending on weather conditions this inlet may be blocked by a berm from the lake waters, and again depending on weather conditions the water inside the berm may be significantly warmer than Lake Michigan which is rather cold until August.
As the South Unit is not in an actual municipality, the police protection is provided by the Lake County Sheriff's Department. The fire and emergency medical services are provided by the Beach Park Fire Department. The water is supplied by the City of Zion, and telephone service is through the Waukegan switch. The North Unit is in Winthrop Harbor, Illinois which provides primary police and fire/emergency medical services. Both properties also fall under the jurisdiction of the Illinois Department of Conservation Police. Water service is also provided by Zion and phone service comes thorough the Zion/Winthrop Harbor switch.