Beaver Dam State Park is an Illinois state park on 750 acres (304 ha) in Macoupin County, Illinois in the United States. The park is 7 miles (11 km) southwest of Carlinville, Illinois and is managed by the Illinois Department of Natural Resources (IDNR) as a public place for fishing. Beaver Dam State Park preserves part of the historic oak-hickory forests that line upper Macoupin Creek. There are 8 miles (13 km) of hiking trails in the park. The reservoir and park drain into a tributary of Macoupin Creek.