| Carlyle Lake | Clinton | 23,710 |
| Kaskaskia River State Fish and Wildlife Area | Randolph +1 | 16,770 |
| Jim Edgar Panther Creek State Fish and Wildlife Area | Cass | 16,550 |
| Sanganois State Fish and Wildlife Area | Mason | 11,150 |
| Copperhead Hollow State Wildlife Area | — | 9,085 |
| Horseshoe Lake-Alexander State Fish and Wildlife Area | Alexander | 8,410 |
| Midewin National Tallgrass Prairie | Will | 7,836 |
| Rend Lake Federal Land | — | 7,740 |
| Rice Lake State Fish and Wildlife Area | Fulton | 7,115 |
| Marshall State Fish and Wildlife Area | Marshall | 6,430 |
| Ten Mile Creek State Fish and Wildlife Area | Hamilton +1 | 5,940 |
| Des Plaines State Fish and Wildlife Area | Will | 4,531 |
| Burning Star State Fish and Wildlife Area | — | 4,508 |
| Banner Marsh State Fish and Wildlife Area | Peoria +1 | 4,361 |
| Horseshoe Lake - Alexander Co. State Fish and Wildlife Area | — | 4,190 |
| Sahara Woods State Fish and Wildlife Area | Saline | 4,059 |
| Kinkaid Lake State Fish and Wildlife Area | — | 3,700 |
| Iroquois County State Fish and Wildlife Area | Iroquois +1 | 2,946 |
| Middle Fork State Fish and Wildlife Area | Vermilion | 2,818 |
| Mazonia-Braidwood State Fish and Wildlife Area | Kankakee | 2,816 |
| Union County State Fish and Wildlife Area | — | 2,800 |
| Sugar River | Winnebago | 2,771 |
| Devil's Island State Fish and Wildlife Area | — | 2,741 |
| Prairie Ridge-Jasper State Natural Area | Jasper | 2,666 |
| Marseilles State Fish and Wildlife Area | — | 2,576 |
| Green River State Wildlife Area | Lee | 2,529 |
| Snakeden Hollow State Fish and Wildlife Area | Knox | 2,487 |
| Henderson Creek State Fish and Wildlife Area | — | 2,441 |
| Big Bend State Fish and Wildlife Area | — | 2,404 |
| Anderson Lake State Fish and Wildlife Area | Fulton +1 | 2,385 |
| Turkey Bluffs State Fish and Wildlife Area | Randolph | 2,284 |
| Lake DePue State Fish and Wildlife Area | Bureau | 2,231 |
| Embarras River Bottoms State Habitat Area | Lawrence | 2,179 |
| Mermet Lake State Fish and Wildlife Area | Massac | 2,153 |
| Spring Lake | Tazewell | 2,123 |
| Chouteau Island State Fish and Wildlife Area | Madison | 2,118 |
| Nature Conservancy | Fulton | 2,054 |
| Double "T" State Fish and Wildlife Area | Fulton | 1,966 |
| Peabody River King State Fish and Wildlife Area | St. Clair | 1,888 |
| Robert Allerton Park | Piatt | 1,808 |
| Ray Norbut State Fish and Wildlife Area | Scott +1 | 1,803 |
| Paul Douglas Preserve | Cook | 1,785 |
| Springbrook Prairie | DuPage | 1,763 |
| Ramsey Lake State Recreation Area | Fayette | 1,759 |
| Piatt County Unit State Fish and Wildlife Area | Piatt | 1,753 |
| Richardson Wildlife Preserve | Lee | 1,735 |
| Hamilton County State Fish and Wildlife Area | Hamilton | 1,669 |
| Richland County Wildlife Management Area | Richland | 1,547 |
| Sand Prairie-Scrub Oak State Natural Area | Mason | 1,509 |
| Devil's Island tate Fish and Wildlife Area | Alexander | 1,503 |
| Powerton lake State Fish and Wildlife Area | Tazewell | 1,471 |
| Washington County State Natural Area | Washington | 1,465 |
| 12 Mile Island Wildlife Management Area - Glades | Jersey | 1,419 |
| Cape Bend State Fish and Wildlife Area | Alexander | 1,390 |
| Witkowsky (Iris and Jack Witkowsky) State Fish and Wildlife Area | — | 1,339 |
| Pratts Wayne Woods | DuPage | 1,326 |
| Sam Dale Lake State Conservation Area | Wayne | 1,324 |
| Witkowsky State Fish and Wildlife Area | Jo Daviess | 1,323 |
| Saline County State Conservation Area | Saline | 1,273 |
| Carlyle Lake State Fish and Wildlife Area | Fayette | 1,251 |
| South Greenbelt Preserve | Cook | 1,244 |
| Fox River Fen | Kane | 1,207 |
| Red's Landing | Calhoun | 1,189 |
| Silver Springs | Kendall | 1,189 |
| Sam Parr State Fish and Wildlife Area | Jasper | 1,164 |
| Crawford County State Fish and Wildlife Area | Crawford | 1,123 |
| McCulley Heritage Project | Calhoun | 1,118 |
| Braidwood Lake State Fish and Wildlife Area | — | 1,100 |
| Pekin Lake | Peoria | 1,095 |
| Red Wing Slough | Lake | 1,001 |
| Edward R. Madigan State Park | Logan | 970 |
| Crabtree Nature Center | Cook | 952 |
| Mautino State Fish and Wildlife Area | Bureau | 913 |
| Piasa Island Wildlife Management Area | Jersey | 912 |
| Newton Lake | Jasper | 879 |
| Heidecke Lake State Fish and Wildlife Area | Grundy | 839 |
| Fults Hill Prairie State Natural Area | Monroe | 810 |
| Herrick Lake Forest Preserve | DuPage | 772 |
| Wildcat Hollow State Habitat Area | Effingham | 748 |
| Woodford State Fish and Wildlife Area | Tazewell | 735 |
| Merwin Preserve | McLean | 711 |
| Sanganois | Cass +1 | 707 |
| Momencee Wetlands State Natural Area | Kankakee | 667 |
| Saybrook State Habitat Area | McLean | 649 |
| Detweiller Woods Nature Preserve | Peoria | 643 |
| Sibley Pheasant Habitat Area | — | 643 |
| Tinely Creek Preserve | Cook | 599 |
| Spring Lake Nature Preserve | Cook | 564 |
| Donnelley State Fish and Wildlife Area | Putnam | 561 |
| Weldon Springs State Park | De Witt | 550 |
| Pleasant Valley 11 | McHenry | 539 |
| Coffeen Lake State Fish and Wildlife Area | Montgomery | 536 |
| Campbell Pond State Habitat Area | Jackson | 529 |
| Mississippi River State Forest Wildlife Area - Mortland | Calhoun | 526 |
| Nelson Lake Marsh | Kane | 520 |
| Goodenow Grove Nature Preserve | Will | 514 |
| Cretaceous Hills State Natural Area | Pope | 511 |
| Cap Sauers Holdings Nature Preserve | Cook | 504 |
| Edward M. Sneed Preserve | Cook | 500 |
| Potato Hill Natural Area | Monroe | 499 |
| Busse Forest Nature Preserve | Cook | 470 |
| Springs Slough | Whiteside | 455 |
| Glacial Park Nature Preserve | McHenry | 446 |
| Wadsworth Prairie Nature Preserve | Lake | 446 |
| MacArthur Woods Nature Preserve | Lake | 426 |
| Revis Hill Prairie State Natural Area | Mason | 423 |
| Ray Norbut - Dutch Creek Unit - State Fish and Wildlife Area | — | 410 |
| East Fork Management Unit State Fish and Wildlife Area | Clinton | 403 |
| Forest Park Nature Preserve | Peoria | 392 |
| Wilmington Shrub Prairie State Natural Area | Will | 390 |
| White Pines Forest State Park | Ogle | 389 |
| Stemler Cave Woods State Natural Area | St. Clair | 386 |
| Hurricane Creek State Habitat Area | Coles | 385 |
| Cranberry Slough Nature Preserve | Cook | 385 |
| Hurricane Creek, Paul C. Burrus | — | 384 |
| Carpenter Park Nature Preserve | Sangamon | 383 |
| Stubblefield Woodlots Nature Preserve | McLean | 382 |
| Finfrock State Habitat Area | — | 377 |
| Black Crown Marsh State Natural Area | McHenry | 374 |
| Sparks Pond State Natural Area | Mason | 373 |
| Fish Lake And Marl Flat Forest Preserve | Lake | 361 |
| Thorton-Lansing Road Nature Preserve | Cook | 349 |
| Ward's Grove State Natural Area | Jo Daviess | 337 |
| Braidwood Dunes and Savanna Nature Preserve | Will | 333 |
| Meredosia Lake State Fish and Wildlife Area | Morgan | 333 |
| Big Grand Pierre Glade State Natural Area | Pope | 331 |
| Sam And Florence Atkinson Forest | Wayne | 324 |
| Channel Lake | Lake | 322 |
| Sand Prairie Pheasant Habitat Area | — | 316 |
| John J. Duffy Preserve | Cook | 315 |
| Jarrett Prairie Nature Preserve | Ogle | 312 |
| Nippersink 1 | Lake | 306 |
| Truitt-Hoff Nature Preserve | DuPage | 304 |
| John M. Olin Nature Preserve | Madison | 296 |
| Buffalo Prairie State Fish and Wildlife Area | Knox | 292 |
| Salt Creek Woods Nature Preserve | Cook | 286 |
| Howard Colman Hall Creek Preserve | Ogle | 280 |
| Mohr Preserve | McLean | 278 |
| Kickapoo Woods | Cook | 266 |
| Hitts Siding Prairie State Natural Area | Will | 260 |
| Calumet Woods | Cook | 258 |
| Dan Ryan Woods | Cook | 255 |
| Sand Ridge Savanna Nature Preserve | Will | 253 |
| Sagawau Canyon | Cook | 251 |
| Victoria Pheasant Habitat Area | — | 244 |
| Prairie State Eagle Refuge State Natural Area | Hancock | 243 |
| Lussky Marsh | McHenry | 241 |
| Elton E. Fawks Bald Eagle Refuge State Natural Area | Rock Island | 240 |
| Victoria State Habitat Area | Knox | 239 |
| Mason State Tree Nursery NC | Mason | 238 |
| Crooked River Forest Preserve | Winnebago | 237 |
| Levee Lake | Madison | 233 |
| Skinner Farm State Habitat Area | Johnson | 227 |
| Putnam County Conservation Area | Bureau | 222 |
| Dog Island State Wildlife Management Area | — | 220 |
| Ozark Hills Nature Preserve | Union | 217 |
| Fall Creek Scenic Overlook State Natural Area | Adams | 214 |
| Kamp's Glade | Calhoun | 214 |
| Maxine Roy Land and Water Reserve | — | 213 |
| Willow Creek State Habitat Area | Edgar | 207 |
| Pecumsaugan Creek/ Blackball Mines State Natural Area | LaSalle | 207 |
| Baker's Lake Nature Preserve | Cook | 204 |
| Piney Creek Ravine State Natural Area | Randolph | 202 |
| Queen Anne Macrosite | McHenry | 199 |
| Funks Grove State Natural Area | McLean | 197 |
| Bates Fen Nature Preserve | McHenry | 195 |
| Warbler Woods Nature Preserve | Coles | 192 |
| Rock Run Rookery Preserve 1 | Will | 192 |
| T-Lake State Fish and Wildlife Area | Knox | 190 |
| Nippersink Lake Open Space | Lake | 188 |
| Sterne's Fen Nature Preserve | McHenry | 187 |
| Stony Hills Nature Preserve | Hancock | 186 |
| Russell M. Duffin Nature Preserve | Vermilion | 184 |
| St. Paul's Forest Preserve | Cook | 182 |
| Sugar River Alder Nature Preserve | Winnebago | 179 |
| Oak Forest Heritage Preserve | Cook | 178 |
| Freeman Mine State Habitat Area | Montgomery | 178 |
| Forest Park South Nature Preserve | Peoria | 177 |
| Burnham Woods Golf Course | Cook | 177 |
| Gibbons Creek Barrens State Natural Area | Pope | 175 |
| Lexington Preserve | McLean | 172 |
| Nelson Lake Marsh Nature Preserve | Kane | 170 |
| Messerling Wildlife Preserve | Peoria | 167 |
| Evans-Judge Preserve 2 | Will | 164 |
| Paw Paw Woods Nature Preserve | Cook | 162 |
| Loda Pheasant Habitat Area | — | 160 |
| Maytown Pheasant Habitat Area | — | 158 |
| Rocky Branch Nature Preserve | Clark | 157 |
| Margaret Guzy Pothole Wetlands State Natural Area | Shelby | 156 |
| Maytown State Habitat Area | Lee | 154 |
| Goose Lake 5 | McHenry | 153 |
| Kankakee Sands Preserve 2 | Will | 152 |
| Dixie Fromm Briggs Prairie Nature Preserve | Kane | 151 |
| Franklin Kenyon Preserve | Woodford | 151 |
| Batchtown Fish and Wildlife Area | Calhoun | 151 |
| La Rue Swamp Nature Preserve | Union | 149 |
| Lower Fox River-Wedron Palisades Nature Preserve | LaSalle | 148 |
| Commonwealth Edison Prairie | Ogle | 147 |
| Little Rock Creek State Habitat Area | Carroll | 147 |
| Rock Cave State Natural Area | Effingham | 143 |
| Sand Ridge Savanna Preserve 2 | Will | 142 |
| Fel-Pro RRR 2 | McHenry | 140 |
| Herschel Workman State Habitat Area | Vermilion | 136 |
| Parkside Preserve | DeKalb | 135 |
| J. Norman Jensen Forest Preserve | Winnebago | 135 |
| Pyles Fork Nature Preserve | Jackson | 135 |
| Herschel Workman Pheasant Habitat Area | — | 135 |
| Oakdale Nature Preserve | Stephenson | 134 |
| Mississippi River - Cordova | Rock Island | 133 |
| DGP Donohue Grove Preserve 2 | Will | 133 |
| Golden Eagle Wildlife Preserve | Calhoun | 131 |
| Blackmon Wildlife Preserve | Peoria | 130 |
| Fen Nature Preserve | McHenry | 127 |
| Powderhorn Prairie and Marsh Nature Preserve | Cook | 127 |
| Lusk Creek Canyon State Natural Area | Pope | 127 |
| Silver Creek Preserve | Winnebago | 126 |
| Bull Valley State Fish & Wildlife Area | McHenry | 126 |
| McKee Marsh | DuPage | 126 |
| Joe Louis "The Champ" Golf Course | Cook | 125 |
| Crawford County Forest Preserve | Crawford | 124 |
| Kennicott's Grove | Cook | 124 |
| Hickory Knolls Natural Area | Kane | 124 |
| Dublin Highlands State Habitat Area | Stephenson | 124 |
| Jurgensen Woods North Nature Preserve | Cook | 124 |
| Perdueville Pheasant Habitat Area | — | 124 |
| Perdueville State Habitat Area | Ford | 123 |
| Prairie Ridge-Marion State Natural Area | Marion | 122 |
| Whitefield Pheasant Habitat Area | — | 120 |
| Calamus Lake State Natural Area | Macon | 118 |
| Robeson Hills Nature Preserve | Lawrence | 117 |
| Stickney Run 2 | McHenry | 117 |
| Jay Woods Forest Preserve | Kendall | 116 |
| Blair Woods | Lake | 115 |
| Wagon Lake State Natural Area | St. Clair | 114 |
| Nippersink Canoe Base 26 | McHenry | 114 |
| Kinnikinnick Creek Nature Preserve | Boone | 112 |
| Mississippi River State Forest Wildlife Area - Red's Landing - Kelly #1 | Calhoun | 110 |
| Crow's Foot State Fish and Wildlife Area | Boone | 109 |
| Hagaman Marsh | Macoupin | 108 |
| Beling Ecological Preserve | Rock Island | 107 |
| Oakford State Habitat Area | Menard | 107 |
| Eagle Park Marsh | Madison | 106 |
| Bradford State Habitat Area | Stark | 103 |
| Gifford Pheasant Habitat Area | — | 103 |
| Powderhorn Lake and Prairie | Cook | 101 |
| Bradford Pheasant Habitat Area | — | 101 |
| Providence Woods Natural Area | Greene | 100 |
| Michael J. O'Malley Preserve | Cook | 100 |
| Bluff Spring Fen Nature Preserve | Cook | 97 |
| Isle a la Cache | Will | 96 |
| Black Hawk Forest Nature Preserve | Rock Island | 96 |
| Hanging Rock Sandstone Cliff State Natural Area | Clay | 94 |
| Windance Acres Marsh | Lake | 93 |
| Sidney R. Yates Flatwoods | Cook | 93 |
| Sweeney Woods Preserve | McLean | 92 |
| Howard D. Colman Dells Preserve | Ogle | 91 |
| Henderson County State Fish and Wildlife Area | Henderson | 91 |
| Horseshoe Lake-Madison State Fish and Wildlife Area | Madison | 91 |
| La Chateau Park | Henry | 90 |
| Lily Lake | McHenry | 88 |
| Alvah Borah State Habitat Area | Wayne | 88 |
| Sundrop Prairie Nature Preserve | Cook | 88 |
| Nature Preserve | Bond | 87 |
| Foggy Bottom | Fulton | 87 |
| Johnson's Mound Nature Preserve | Kane | 87 |
| Hindsboro State Habitat Area | Douglas | 87 |
| Goodenow Grove Nature Preserve 5 | Will | 87 |
| Long Branch Sand Prairie State Natural Area | Mason | 86 |
| Saybrook Pheasant Habitat Area | — | 86 |
| Hindsboro Pheasant Habitat Area | — | 86 |
| Camp Vandeventer | Monroe | 84 |
| Dean Hills State Natural Area | Fayette | 84 |
| Hallsville State Pheasant Area | — | 84 |
| Boone Creek Fen Nature Preserve | McHenry | 83 |
| Matanzas Prairie State Natural Area | Mason | 83 |
| Clifton State Habitat Area | Iroquois | 82 |
| Tangley Oaks Woods | Lake | 81 |
| Krause Woods Natural Area | Calhoun | 81 |
| Swayne Hollow State Natural Area | Randolph | 81 |
| Marengo Ridge 5 | McHenry | 81 |
| Steward Pheasant Habitat Area | — | 81 |
| Manito Pheasant Habitat Area | — | 81 |
| Wayne Lehnert Preserve | Will | 80 |
| Ephgrave Cave | Union | 80 |
| Steward State Habitat Area | Lee | 80 |
| Long Run Seep State Natural Area | Will | 80 |
| O'Hara Woods Nature Preserve | Will | 80 |
| Burton Cave State Natural Area | Adams | 79 |
| Milk's Grove State Fish and Wildlife Area | Iroquois | 79 |
| Reed Wildlife State Habitat Area | Hancock | 79 |
| Fort Sheridan Bluff | Lake | 78 |
| Manito State Habitat Area | Tazewell | 78 |
| Lyndon Prairie | Whiteside | 77 |
| River Retreat | Calhoun | 77 |
| Goodenow Grove | Will | 76 |
| Birkbeck Pheasant Habitat Area | — | 76 |
| Milks Grove Pheasant Habitat Area | — | 76 |
| Jackson Slough Woods State Natural Area | St. Clair | 75 |
| Trelease Woods | Champaign | 74 |
| Gillespie Prairie State Natural Area | Macoupin | 74 |
| Material Services Prairie | Will | 73 |
| Paintbrush Prairie Nature Preserve | Cook | 73 |
| Somme Prairie Nature Preserve | Cook | 72 |
| Meeker (Cecil E.) State Habitat Area | — | 72 |
| Stickney Run 14 | McHenry | 70 |
| Sand Ridge Nature Preserve | Cook | 70 |
| Wolf Preserve | Menard | 69 |
| Stickney Run 3 | McHenry | 69 |
| Cecil E. Meeker State Habitat Area | Jasper | 68 |
| Josua Lindahl Hill Prairies Nature Preserve | Rock Island | 67 |
| Sandra Miller Bellrose Nature Preserve | Logan | 67 |
| Maramech Woods Nature Preserve | Kendall | 66 |
| Storment Hauss Nature Preserve | Monroe | 65 |
| Elkhart Hill Grove Nature Preserve | Logan | 64 |
| Brownfield Woods | Champaign | 64 |
| Upper Rock 002-06 | Winnebago | 63 |
| Plum Creek Natural Area | Lee | 62 |
| Colored Sands Bluff Nature Preserve | Winnebago | 62 |
| Roman Pucinski Preserve | Cook | 61 |
| Dunn's Lake | Lake | 60 |
| Pecatonica Bottoms Nature Preserve | Winnebago | 60 |
| Shick Shack Sand Pond State Natural Area | Cass | 60 |
| Henline Preserve | McLean | 59 |
| Bowes Creek Woods Forest Preserve 3 | Kane | 59 |
| Plum Island Eagle Sanctuary | LaSalle | 58 |
| McClure Shale Glade Nature Preserve | Union | 58 |
| Churchill Prairie Nature Preserve | DuPage | 57 |
| Clark Run | LaSalle | 54 |
| Ripplinger - Gouker Prairie Preserve | Ogle | 53 |
| Merritt Prairie Forest Preserve | DeKalb | 53 |
| Beck's Woods 7 | McHenry | 52 |
| Spring Bay Fen State Natural Area | Woodford | 50 |
| Wildlife Preserve (Young - A) | Peoria | 49 |
| Prairie Preservation Property | Henry | 49 |
| McClure Preserve | McLean | 49 |
| Barton-Sommer Woodland State Natural Area | Menard | 49 |
| Grubb Hollow Prairie State Natural Area | Pike | 49 |
| Wilkinson-Renwick Marsh Nature Preserve | DeKalb | 48 |
| Etnyre Preserve | Ogle | 47 |
| Reed-Turner Woodland Nature Preserve | Lake | 47 |
| Silver Creek Biodiversity Preserve: Tarbox Unit | Ogle | 47 |
| Hazelwood Forest Nature Preserve | Lee | 47 |
| Iroquois Woods State Natural Area | Kankakee | 46 |
| Wolf Road Prairie State Natural Area | Cook | 46 |
| Ray Norbut State Fish and Wildlife Area - East Hannibal Unit | — | 46 |
| Forest Park Foundation | Tazewell | 45 |
| Doris Westfall Prairie Restoration Nature Preserve | Vermilion | 45 |
| Jordan Creek of the North Fork Nature Preserve | Vermilion | 45 |
| Kilbuck Creek | Ogle | 45 |
| Barrington Bog | Lake | 45 |
| Bois du Sangamon Nature Preserve | Macon | 44 |
| Moosheart Ravine | Kane | 44 |
| Mississippi River Sand Hills State Natural Area | Hancock | 44 |
| Principia Hill Prairies East | — | 44 |
| McMaster Woods | Greene | 44 |
| Prairie Oaks Forest Preserve | DeKalb | 43 |
| Green Meadows Golf Course | DuPage | 43 |
| Palatine Road Marsh State Natural Area | Cook | 43 |
| Millroad Marsh State Habitat Area | Whiteside | 43 |
| Glen D. Palmers State Game Farm | Kendall | 43 |
| Thorn Creek Woods Nature Preserve 4 | Will | 43 |
| Boloria Fen and Sedge Meadow Nature Preserve | McHenry | 42 |
| Oak Openings Nature Preserve | Lake | 42 |
| Nussbaum Prairie | Rock Island | 41 |
| Elkhorn Creek Biodiversity Preserve | Ogle | 41 |
| Moon Preserve | McLean | 41 |
| Ren-Dill Shale Glade Nature Preserve | Union | 41 |
| Robert Ridgway Grasslands Nature Preserve | Jasper | 41 |
| Hartley Memorial Nature Preserve | Winnebago | 40 |
| Hazle Preserve | Woodford | 40 |
| Devil's Prop State Natural Area | Jefferson | 40 |
| Cedar Lake Bog State Natural Area | Lake | 40 |
| Goode's Woods State Natural Area | Macoupin | 40 |
| Harper-Rector Woods State Natural Area | Fulton | 40 |
| Sipple Slough Woods State Natural Area | Washington | 40 |
| Ilo Dillin State Habitat Area | — | 0 |
| Calhoun Point State Fish and Wildlife Area | — | 0 |
| Clear Lake State Fish and Wildlife Area | — | 0 |
| Glades-12 Mile Island | — | 0 |
| Fuller Lake State Wildlife Management Area | — | 0 |
| Godar-Diamond/Huricane Island | — | 0 |
| Rip-Rap Landing | — | 0 |
| Stump Lake State Wildlife Management Area | — | 0 |
| Sinnissippi Lake State Fish and Wildlife Area | — | 0 |
| Buffalo Prairie Pheasant Habitat Area | — | 0 |
| Larry D. Closson (Hickory Ridge) State Habitat Area | — | 0 |
| Mazonia State Fish and Wildlife Area | — | 0 |
| Cahokia Mounds State Historic Site | — | 0 |