The area of Volo Bog State Natural Area is 4,653,884.88576 square meters.
Volo Bog State Natural Area was created in 1970.
The area of Hill Country State Natural Area is 21.728 square kilometers.
The area of Spitler Woods State Natural Area is 819,488.425536 square meters.
The area of Illinois Caverns State Natural Area is 485,622.770688 square meters.
The area of Lost Maples State Natural Area is 8,797,865.8622976 square meters.
The area of Keowee-Toxaway State Natural Area is 4,046,856.4224 square meters.
The area of Kidd Lake State Natural Area is 3,237,485.13792 square meters.
The area of Radnor Lake State Natural Area is 4,856,227.70688 square meters.
The area of Devil's Sinkhole State Natural Area is 7,525,938.888737281 square meters.
The area of Piney Creek Ravine State Natural Area is 801,277.5716352001 square meters.
The area of Stillhouse Hollow Falls State Natural Area is 364,217.078016 square meters.
Hill Country State Natural Area was created in 1984.