s.
s: state parks, state forests, state recreation areas, state fish and wildlife areas, state natural areas, and one state trail. They are all administered by the
.
, including portions of National Trails.
| 'Park Name' | 'County or Counties' | 'Area' in acres (km²) | 'Date founded' | 'Stream(s) and / or Lake(s)' | 'Remarks' |
|---|
| Anderson Lake State Fish & Wildlife Area | | | | | |
| Apple River Canyon State Park | Jo Daviess | 297 acres (1.2 km²) | 1932 | Apple River | |
| Argyle Lake State Park | McDonough | 1700 acres (6.88 km²) | 1948 | Argyle Lake | |
| Baldwin Lake State Fish & Wildlife Area | Randolph County | 2018 acres (8.2 km²) | | Baldwin Lake | |
| Beall Woods State Park | Wabash | 635 acres (2.57 km²) | 1966 | Coffee Creek | |
| Beaver Dam State Park | Macoupin | 750 acres (3.04 km²) | 1947 | Beaver Dam Lake | |
| Big River State Forest | Henderson | 2900 acres (11.74 km²) | 1925 | Mississippi River | |
| Buffalo Rock State Park & Effigy Tumuli | LaSalle County | 298 acres (1.21 km²) | November 15, 1928 | Illinois River | |
| Cache River State Natural Area | | | | | |
| Carlyle Lake State Fish and Wildlife Area | | | | | |
| Castle Rock State Park | Ogle | 2000 acres (8.09 km²) | 1921 | Rock River | |
| Cave-in-Rock State Park | Hardin | 204 acres (0.83 km²) | 1929 | Ohio River | |
| Chain O'Lakes State Park | McHenry | 1700 acres (6.88 km²) | 1945 | Bluff Lake, Catherine Lake, Channel Lake, Fox Lake, Fox River, Grass Lake, Marie Lake, Nippersink Lake, Petite Lake, Pistakee Lake, Redhead Lake, Turner Lake | |
| Channahon State Park | Will | 20.5 acres (0.08 km²) | 1932 | DuPage River, Des Plaines River, Kankakee River | |
| Clinton Lake State Recreation Area | | | | | |
| Coffeen Lake State Fish and Wildlife Area | | | | | |
| Crawford County State Fish and Wildlife Area | | | | | |
| Delabar State Park | Henderson | 89 acres (0.36 km²) | 1960 | | |
| Des Plaines Fish and Wildlife Area | | | | | |
| Dixon Springs State Park | Pope | 801 acres | 1946 | | |
| Donnelley/Depue State Park | Putnam | | | | |
| Eagle Creek State Recreation Area | | | | | |
| Edward R. Madigan State Fish and Wildlife Area | Lincoln | 974-acre (3.8 km²) | 1971 | Salt Creek | |
| Eldon Hazlet State Recreation Area | | | | | |
| Ferne Clyffe State Park | Johnson | 2,430 acres (9.83 km²) | 1949 | | |
| Fort Massac State Park | Massac | 1,450 acres (5.87 km²) | 1908 | Ohio River | |
| Fox Ridge State Park | Coles | 2,064 acres (8.35 km²) | 1930s | | |
| Frank Holten State Recreation Area | | | | | |
| Franklin Creek State Park | Lee | 664 acres (2.69 km²) | 1970 | | |
| Fults Hill Prairie State Natural Area | | | | | |
| Gebhard Woods State Park | Grundy | 30 acres (0.12 km²) | 1934 | | |
| Giant City State Park | Jackson & Union | 1,100 acres (4.45 km²) | 1927 | | |
| Golconda Marina State Recreation Area | | | | | |
| Goose Lake Prairie State Natural Area | Grundy | 2,537-acre (10.3 km²) | 1969 | | |
| Green River State Wildlife Area | | | | | |
| Hamilton County State Fish and Wildlife Area | | | | | |
| Harry "Babe" Woodyard State Natural Area | | | | | |
| Hazel & Bill Rutherford Wildlife Prairie State Park | Peoria | 1,700 acres (6.88 km²) | 2000 | | |
| Heidecke Lake State Fish & Wildlife Area | | | | | |
| Hennepin Canal Parkway State Park | | | | | |
| Hidden Springs State Forest | Shelby | 1200 acres (4.86 km²) | 1960 | Richland Creek, Possum Creek | |
| Horseshoe Lake State Fish & Wildlife Area | | | | | |
| Horseshoe Lake State Park | Madison | 2,960 acres (11.98 km²) | | | |
| Illini State Park | LaSalle | 510 acres (2.06 km²) | 1934 | | |
| Illinois Beach State Park | Lake County, Illinois | 4,160 acres (16.83 km²) | 1948 | Lake Michigan | |
| Illinois Caverns State Natural Area | Monroe | 120 acres/9.6 km of passages | 1985 | | |
| Iroquois State Wildlife Area | | | | | |
| James "Pate" Philip State Park | | | | | |
| Jim Edgar Panther Creek State Fish and Wildlife Area | | | | | |
| Johnson-Sauk Trail State Park | | | | | |
| Jubilee College State Park | | | | | |
| Kankakee River State Park | Kankakee and Will | 4000 acres (16.19 km²) | 1938 | Kankakee River | |
| Kaskaskia River State Fish & Wildlife Area | | | | | |
| Kickapoo State Recreation Area | | | | | |
| Kinkaid Lake State Fish and Wildlife Area | | | | | |
| Kishwaukee River State Fish & Wildlife Area | | | | | |
| Lake Le-Aqua-Na State Park | | | | | |
| Lake Murphysboro State Park | | | | | |
| LaSalle Lake State Fish & Wildlife Area | | | | | |
| Lincoln Trail Homestead State Memorial | | | | | |
| Lincoln Trail State Park | Clark | | 1958 | Lincoln Trail Lake | |
| Lowden State Park | | | | | |
| Mackinaw River State Fish and Wildlife Area | | | | | |
| Mackinaw River State Fish and Wildlife Area | | | | | |
| Marshall State Fish & Wildlife Area | | | | | |
| Matthiessen State Park | | | | | |
| Mautino State Fish & Wildlife Area | | | | | |
| Mazonia/Braidwood State Fish & Wildlife Area | | | | | |
| Mermet Lake State Fish and Wildlife Area | | | | | |
| Middle Fork State Fish and Wildlife Area | | | | | |
| Mississippi Palisades State Park | | | | | |
| Mississippi River State Fish and Wildlife Area | | | | | |
| Moraine Hills State Park | | | | | |
| Moraine View State Recreation Area | | | | | |
| Morrison-Rockwood State Park | | | | | |
| Nauvoo State Park | | | | | |
| Newton Lake State Fish and Wildlife Area | | | | | |
| North Point Marina | | | | | |
| Peabody River State Fish and Wildlife Area | | | | | |
| Pere Marquette State Park | | | | | |
| Piney Creek Ravine State Natural Area | | | | | |
| Prophetstown State Recreation Area | | | | | |
| Pyramid State Recreation Area | | | | | |
| Ramsey Lake State Recreation Area | | | | | |
| Randolph County State Recreation Area | | | | | |
| Ray Norbut State Fish and Wildlife Area | | | | | |
| Red Hills State Park | | | | | |
| Rend Lake State Fish and Wildlife Area | | | | | |
| Rice Lake State Fish and Wildlife Area | | | | | |
| Rock Cut State Park | | | | | |
| Rock Island Trail State Park | | | | | |
| Saline County State Fish & Wildlife Area | | | | | |
| Sam Dale Lake State Fish and Wildlife Area | | | | | |
| Sam Parr State Fish and Wildlife Area | | | | | |
| Sand Ridge State Forest | Mason | 7,200 acres (29 km²) | 1939 | None | |
| Sanganois State Fish and Wildlife Area | | | | | |
| Sangchris Lake State Recreation Area | | | | | |
| Shabbona Lake State Park | | | | | |
| Shelbyville State Fish and Wildlife Area | | | | | |
| Sielbeck Forest Natural Area | | | | | |
| Siloam Springs State Park | | | | | |
| Silver Springs State Fish & Wildlife Area | | | | | |
| Snakeden Hollow State Fish and Wildlife Area | | | | | |
| South Shore State Park | | | | | |
| Spitler Woods State Natural Area | | | | | |
| Spring Lake Fish and Wildlife Area | | | | | |
| Starved Rock State Park | | | | | |
| Stephen A. Forbes State Recreation Area | | | | | |
| Ten Mile Creek State Fish & Wildlife Area | | | | | |
| Trail of Tears State Forest | Union | 5114 acres (20.7 km²) | 1929 | Mississippi River, Clear Creek | |
| Tunnel Hill State Trail | | | | | |
| Turkey Bluffs State Fish and Wildlife Area | | | | | |
| Union County State Fish and Wildlife Area | | | | | |
| Volo Bog State Natural Area | | | | | |
| Walnut Point State Park | | | | | |
| Washington County State Recreation Area | | | | | |
| Wayne Fitzgerrell State Recreation Area | | | | | |
| Weinberg-King State Park | | | | | |
| Weldon Springs State Recreation Area | | | | | |
| White Pines Forest State Park | Ogle | 385 acres (1.56 km²) | 1927 | Pine Creek, Spring Creek | Southernmost stand of virgin, native white pine trees in the state of Illinois.["Conserving the Land: The Rock River Country," Critical Trends Assessment Program, Rock River Country Project ([1]), ''Illinois Department of Natural Resources'', 3 July 2007.] |
| William G. Stratton State Park | | | | | |
| William W. Powers State Recreation Area | | | | | |
| Wolf Creek State Park | | | | | |
| Woodford State Fish and Wildlife Area | | | | | |