| NUMBER | NAME | COUNTY | LAT | LON |
| IL12 | Andalusia Island | Rock Island | 412656N | 0904820W |
| IL01 | Angelo Towhead | Alexander | 365846N | 0891031W |
| IL13 | Apple River Island | Carroll | 421032N | 0901514W |
| IL03 | Arsenal Island | St. Clair | 383358N | 0901318W |
| IL14 | Aux Sable Island | Grundy | 412243N | 0882015W |
| IL09 | Bar Island | Cass | 400011N | 0902856W |
| IL14 | Bardwell Island | Will | 412128N | 0881355W |
| IL12 | Barkis Island | Mercer | 411728N | 0910457W |
| IL15 | Barney Island | Lake | 422637N | 0880951W |
| IL08 | Barns Island | Adams | 400637N | 0912915W |
| IL14 | Barry Island | Grundy | 411924N | 0883320W |
| IL12 | Bass Island | Mercer | 411937N | 0910409W |
| IL08 | Bay Island | Pike | 393250N | 0910605W |
| IL03 | Beagles Island | Monroe | 380758N | 0901438W |
| IL12 | Beaver Island | Rock Island | 412803N | 0903536W |
| IL10 | Beaver Island | Henderson | 404310N | 0910635W |
| IL03 | Beaver Island | Randolph | 375746N | 0895541W |
| IL08 | Beebe Island | Adams | 394909N | 0912251W |
| IL12 | Bell Island | Mercer | 411325N | 0910522W |
| IL14 | Bells Island | La Salle | 411944N | 0884410W |
| IL10 | Benton Island | Henderson | 405838N | 0905656W |
| IL08 | Big Blue Island | Pike | 393951N | 0903738W |
| IL10 | Big Dasher Island | Henderson | 405400N | 0910017W |
| IL10 | Big Dasher Island | Henderson | 405413N | 0905931W |
| IL12 | Big Island | Rock Island | 412740N | 0903613W |
| IL01 | Big Muddy Island | Jackson | 373436N | 0892939W |
| IL13 | Blackhawk Island | Winnebago | 421228N | 0890542W |
| IL12 | Blanchard Island | Rock Island | 412117N | 0910344W |
| IL10 | Blue Goose Island | Hancock | 401205N | 0912955W |
| IL12 | Bogus Island | Mercer | 411532N | 0910548W |
| IL13 | Boney Island | Winnebago | 422919N | 0890250W |
| IL01 | Boss Island | Pulaski | 372142N | 0885724W |
| IL15 | Boy Scout Island | Kane | 415510N | 0881905W |
| IL09 | Briar Island | Cass | 400319N | 0901259W |
| IL04 | Bridge Island | Greene | 392737N | 0903646W |
| IL08 | Browns Island | Pike | 393758N | 0911412W |
| IL08 | Brownsville Island | Adams | 401032N | 0913005W |
| IL04 | Buckhorn Island | Greene | 392959N | 0903517W |
| IL02 | Bull Island | White | 380944N | 0875511W |
| IL14 | Bulls Island | La Salle | 412027N | 0884914W |
| IL01 | Bumgard Island | Alexander | 370234N | 0892143W |
| IL10 | Burlington Island | Henderson | 404345N | 0910613W |
| IL01 | Burnham Island | Alexander | 370830N | 0892445W |
| IL10 | Buzzard Island | Hancock | 401422N | 0912949W |
| IL12 | Buzzard Island | Mercer | 411342N | 0910533W |
| IL03 | Calico Island | Monroe | 381237N | 0902020W |
| IL12 | Campbells Island | Rock Island | 413231N | 0902545W |
| IL05 | Campbells Island | Calhoun | 390525N | 0904033W |
| IL12 | Carr Island | Rock Island | 412740N | 0903316W |
| IL05 | Carroll Island | Calhoun | 392008N | 0904924W |
| IL05 | Carroll Island | Calhoun | 392015N | 0904930W |
| IL08 | Cash Island | Pike | 392513N | 0905817W |
| IL15 | Cedar Island | Lake | 422522N | 0880512W |
| IL15 | Cedar Island | Lake | 422255N | 0881125W |
| IL08 | Chatton Island | Adams | 400710N | 0912920W |
| IL07 | Chillicothe Island | Woodford | 405439N | 0892842W |
| IL04 | Chouteau Island | Madison | 384607N | 0900847W |
| IL15 | Clark Island | Kane | 415039N | 0881828W |
| IL15 | Clark Island | Putnam | 411913N | 0891524W |
| IL14 | Clarks Island | La Salle | 411907N | 0884130W |
| IL05 | Clarksville Island | Calhoun | 392210N | 0905257W |
| IL10 | Clifford Island | Henderson | 404328N | 0910623W |
| IL08 | Coal Creek Island | Schuyler | 400004N | 0902940W |
| IL12 | Coleman Island | Mercer | 411512N | 0910632W |
| IL14 | Conroy Island | Will | 412400N | 0881335W |
| IL07 | Coon Hollow Island | Tazewell | 403117N | 0895114W |
| IL05 | Coon Island | Calhoun | 391915N | 0904820W |
| IL15 | Coon Islands | McHenry | 422246N | 0881220W |
| IL07 | Coopers Island | Tazewell | 403433N | 0893908W |
| IL08 | Cottonwood Island | Pike | 393237N | 0910613W |
| IL15 | Crabapple Island | Lake | 422447N | 0880952W |
| IL10 | Craigel Island | Henderson | 404455N | 0910613W |
| IL03 | Crains Island | Randolph | 375142N | 0894640W |
| IL04 | Crater Island | Greene | 391542N | 0903627W |
| IL01 | Crawford Towhead | Union | 373212N | 0893021W |
| IL08 | Crider Island | Pike | 392538N | 0905940W |
| IL09 | Cuba Island | Cass | 400419N | 0901716W |
| IL10 | Dallas Island | Henderson | 403844N | 0910956W |
| IL05 | Dead Mans Island | Calhoun | 391721N | 0904559W |
| IL08 | Deadman Island | Adams | 395917N | 0912720W |
| IL14 | Delbridge Island | La Salle | 411902N | 0885527W |
| IL08 | Denmark Island | Pike | 393318N | 0910910W |
| IL13 | Denton Island | Winnebago | 421514N | 0890604W |
| IL01 | Devils Island | Alexander | 371947N | 0892655W |
| IL05 | Diamond Island | Calhoun | 391144N | 0903552W |
| IL08 | Dillon Island | Adams | 400634N | 0912938W |
| IL13 | Dixie Islands | Carroll | 420239N | 0900928W |
| IL05 | Dog Island | Calhoun | 391552N | 0904404W |
| IL01 | Dogtooth Island | Alexander | 370110N | 0891656W |
| IL14 | Dresden Island | Grundy | 412357N | 0881707W |
| IL08 | Drift Island | Pike | 393312N | 0910755W |
| IL11 | Duck Island | Fulton | 402742N | 0895601W |
| IL02 | Duck Island | Wabash | 382157N | 0874810W |
| IL03 | Eagle Island | Morgan | 395209N | 0903500W |
| IL14 | Eagle Island | Kankakee | 410845N | 0874321W |
| IL08 | Eagle Island | Pike | 393249N | 0910814W |
| IL06 | Eagle Island | Crawford | 390140N | 0873423W |
| IL04 | Eagles Nest Island | Jersey | 385539N | 0901807W |
| IL08 | Elm Island | Schuyler | 400740N | 0902056W |
| IL05 | Enterprise Island | Calhoun | 385523N | 0902936W |
| IL04 | Fisher Island | Greene | 392323N | 0903652W |
| IL15 | Five Islands | Kane | 415807N | 0881814W |
| IL08 | Flannigan Island | Adams | 400238N | 0912741W |
| IL03 | Fort Chartres Island | Randolph | 380451N | 0901017W |
| IL08 | Fourmile Island | Pike | 394042N | 0911733W |
| IL02 | Fox Island | White | 380852N | 0875846W |
| IL04 | Gabaret Island | Madison | 384256N | 0901048W |
| IL01 | Giboney Island | Alexander | 371721N | 0893049W |
| IL10 | Gilligans Island | Hancock | 403245N | 0912253W |
| IL15 | Goose Island | Cook | 415414N | 0873914W |
| IL15 | Goose Island | Cook | 415413N | 0873912W |
| IL01 | Goose Island | Alexander | 370732N | 0892411W |
| IL08 | Gosline Island | Pike | 392558N | 0910010W |
| IL09 | Grand Island | Mason | 401205N | 0900848W |
| IL09 | Grange Island, La | Cass | 395604N | 0903202W |
| IL08 | Grange Island, La | Adams | 400232N | 0912919W |
| IL09 | Grape Island | Cass | 400023N | 0902801W |
| IL14 | Grape Island | Will | 412138N | 0881355W |
| IL15 | Grass Island | Lake | 422703N | 0880939W |
| IL05 | Grimes Island | Calhoun | 391808N | 0904705W |
| IL14 | Grist Island | Grundy | 412003N | 0883009W |
| IL15 | Hackberry Island | Lake | 422744N | 0881006W |
| IL10 | Hackley Island | Hancock | 401717N | 0912847W |
| IL13 | Hale Island | Jo Daviess | 422044N | 0902600W |
| IL01 | Halfmoon Island | Jackson | 373417N | 0892857W |
| IL15 | Halfmoon Islands | McHenry | 422328N | 0881232W |
| IL01 | Hanging Dog Island | Union | 373055N | 0892938W |
| IL10 | Hardy Bar Island | Hancock | 401233N | 0913010W |
| IL10 | Harper Island | Henderson | 404656N | 0910429W |
| IL05 | Hat Island | Calhoun | 385525N | 0903922W |
| IL07 | Heisner Island | Livingston | 405315N | 0883951W |
| IL05 | Helmbold Island | Calhoun | 390356N | 0903518W |
| IL12 | Hershey Island | Rock Island | 412538N | 0905749W |
| IL09 | Hickory Island | Mason | 400806N | 0901943W |
| IL14 | Hitt Island | La Salle | 412013N | 0885138W |
| IL14 | Hoffman Island | Will | 411358N | 0880444W |
| IL08 | Hogback Island | Adams | 395929N | 0912745W |
| IL10 | Huff Island | Hancock | 401301N | 0912958W |
| IL10 | Hunt Island | Hancock | 401327N | 0912936W |
| IL15 | Hurds Island | Kane | 414502N | 0881925W |
| IL05 | Hurricane Island | Calhoun | 391346N | 0903600W |
| IL12 | Indian Island | Rock Island | 412811N | 0903545W |
| IL14 | Indian Island | La Salle | 412721N | 0884405W |
| IL13 | Indian Island | Whiteside | 414056N | 0895823W |
| IL05 | Iowa Island | Calhoun | 385431N | 0903030W |
| IL13 | Island 228 | Jo Daviess | 422738N | 0903708W |
| IL13 | Island 233 | Jo Daviess | 422509N | 0903221W |
| IL13 | Island 235 | Jo Daviess | 422410N | 0903028W |
| IL13 | Island 266 | Carroll | 420729N | 0900942W |
| IL05 | Island 464 | Calhoun | 392151N | 0905248W |
| IL05 | Island 518 | Calhoun | 385439N | 0903007W |
| IL05 | Island 521 | Calhoun | 385556N | 0902912W |
| IL05 | Island 525 | Calhoun | 385756N | 0902755W |
| IL13 | Island Number 1 | Winnebago | 421309N | 0890549W |
| IL13 | Island Number 254 | Jo Daviess | 421228N | 0902003W |
| IL13 | Island Number 256 | Carroll | 421101N | 0901649W |
| IL01 | Island Number 28 | Alexander | 370504N | 0891646W |
| IL01 | Island Number 29 | Alexander | 370447N | 0891555W |
| IL12 | Island Number 317 | Rock Island | 412710N | 0904120W |
| IL12 | Island Number 318 | Rock Island | 412705N | 0904234W |
| IL12 | Island Number 319 | Rock Island | 412700N | 0904304W |
| IL12 | Island Number 322 | Rock Island | 412647N | 0904503W |
| IL12 | Island Number 328 | Rock Island | 412542N | 0905343W |
| IL12 | Island Number 330 | Rock Island | 412523N | 0905710W |
| IL12 | Island Number 347 | Mercer | 411638N | 0910517W |
| IL08 | Island Number 419 | Adams | 400423N | 0912929W |
| IL09 | Island of Canton | Mason | 401831N | 0900357W |
| IL08 | Jim Young Island | Pike | 393712N | 0911312W |
| IL14 | Johnson Island | La Salle | 411845N | 0883932W |
| IL05 | Johnson Island | Calhoun | 385630N | 0903945W |
| IL12 | Jonas Johnson Island | Mercer | 411252N | 0910438W |
| IL10 | Kamps-Stiens Island | Hancock | 401818N | 0912826W |
| IL03 | Kaskaskia Island | Randolph | 375449N | 0895518W |
| IL05 | Kelly Island | Calhoun | 391204N | 0904242W |
| IL13 | Kempster Island | Whiteside | 413641N | 0900908W |
| IL07 | King Island | Tazewell | 403016N | 0895252W |
| IL09 | Knapps Island | Mason | 400734N | 0901804W |
| IL14 | Koops Island | Kankakee | 410916N | 0874204W |
| IL10 | Kusie Island | Hancock | 402002N | 0912743W |
| IL01 | Lacours Island | Jackson | 374303N | 0893441W |
| IL14 | Langham Island | Kankakee | 411117N | 0875753W |
| IL14 | Leopold Island | La Salle | 411927N | 0885921W |
| IL08 | Libby Island | Adams | 400111N | 0912719W |
| IL14 | Little Dresden Island | Grundy | 412355N | 0881724W |
| IL02 | Little Fox Island | White | 381019N | 0875810W |
| IL01 | Little Island | Alexander | 370803N | 0892445W |
| IL13 | Little Rock Island | Whiteside | 415004N | 0901055W |
| IL08 | Long Island | Adams | 400314N | 0912832W |
| IL04 | Macoupin Island | Greene | 390923N | 0903552W |
| IL12 | Mapes Island | Mercer | 410515N | 0905630W |
| IL05 | Maple Island | Calhoun | 390610N | 0904025W |
| IL14 | Maple Island | Kankakee | 410851N | 0874238W |
| IL13 | Margaret Fuller Island | Ogle | 420140N | 0891955W |
| IL05 | Martin Towhead | Calhoun | 385454N | 0903848W |
| IL04 | Mason Island | Jersey | 385736N | 0902730W |
| IL09 | Matanzas Island | Mason | 401518N | 0900611W |
| IL05 | Maxey Island | Calhoun | 390012N | 0904038W |
| IL14 | Mayo Island | La Salle | 411939N | 0885212W |
| IL05 | McCoy Island | Calhoun | 391728N | 0904617W |
| IL08 | McDonald Island | Adams | 394600N | 0912125W |
| IL03 | McGees Island | Morgan | 395100N | 0903400W |
| IL03 | Meissner Island | Monroe | 381820N | 0902132W |
| IL09 | Meredosia Island | Cass | 395321N | 0903340W |
| IL05 | Middleton Island | Calhoun | 392328N | 0905535W |
| IL10 | Mill Island | Henderson | 405753N | 0905633W |
| IL13 | Millwoods Island | Whiteside | 414012N | 0895828W |
| IL11 | Mink Island | Fulton | 402722N | 0895520W |
| IL11 | Miserable Island | Fulton | 402759N | 0895630W |
| IL01 | Missouri Sister Island | Alexander | 370429N | 0891632W |
| IL13 | Montague Island | Winnebago | 421523N | 0890548W |
| IL14 | Moores Island | La Salle | 412025N | 0884743W |
| IL14 | Moose Island | Will | 412437N | 0881311W |
| IL03 | Moro Island | Randolph | 375932N | 0895935W |
| IL05 | Mortland Island | Calhoun | 390706N | 0903629W |
| IL04 | Mosenthein Island | Madison | 384321N | 0901206W |
| IL13 | Mound Island | Carroll | 420216N | 0900921W |
| IL10 | Mud Island | Hancock | 402232N | 0912449W |
| IL08 | Mud Island | Adams | 401146N | 0912948W |
| IL14 | Mulberry Island | Will | 412144N | 0881434W |
| IL15 | North Aurora Island | Kane | 414820N | 0881924W |
| IL08 | North Fritz Island | Pike | 393140N | 0910500W |
| IL15 | Northerly Island | Cook | 415147N | 0873629W |
| IL13 | Number 249, Island | Jo Daviess | 421344N | 0902325W |
| IL02 | Old River Island | Wayne | 382418N | 0881148W |
| IL10 | Paddy Island | Henderson | 404205N | 0910554W |
| IL14 | Parish Island | Kankakee | 410928N | 0874129W |
| IL14 | Peacocks Island | Grundy | 412150N | 0882327W |
| IL08 | Pearl Island | Pike | 394224N | 0912005W |
| IL06 | Pecan Island | Fayette | 385324N | 0890636W |
| IL12 | Peterson Island | Henry | 413431N | 0901050W |
| IL12 | Pettifer Island | Rock Island | 412902N | 0903639W |
| IL04 | Piasa Island | Jersey | 385551N | 0901638W |
| IL01 | Picayune Island | Alexander | 371958N | 0892522W |
| IL01 | Pine Island | Williamson | 374412N | 0890814W |
| IL14 | Plum Island | La Salle | 411931N | 0885945W |
| IL08 | Polly Island | Adams | 401108N | 0912953W |
| IL15 | Prescotts Island | Cook | 414822N | 0874830W |
| IL15 | Queens Island | Lake | 422259N | 0881112W |
| IL08 | Quinsippi Island | Adams | 395631N | 0912518W |
| IL10 | Ridge, The | Hancock | 403752N | 0911424W |
| IL15 | Riverside Island | Lake | 422424N | 0881116W |
| IL12 | Rock Island | Rock Island | 413112N | 0903232W |
| IL01 | Rock Island | Alexander | 371445N | 0892715W |
| IL03 | Rockwood Island | Randolph | 374807N | 0893953W |
| IL08 | Sand Bar Island | Pike | 393227N | 0910531W |
| IL09 | Sand Island | Mason | 400505N | 0901647W |
| IL13 | Santa Fe Island | Carroll | 420745N | 0901129W |
| IL05 | Sarah Ann Island | Calhoun | 390046N | 0904113W |
| IL13 | Savanna Islands | Carroll | 420326N | 0900944W |
| IL08 | Saverton Island | Pike | 393917N | 0911539W |
| IL08 | Schaffer Island | Adams | 394714N | 0912119W |
| IL14 | Scherer Island | La Salle | 412027N | 0884944W |
| IL13 | Seawards Island | Jo Daviess | 421531N | 0902452W |
| IL11 | Senate Island | Fulton | 402702N | 0895434W |
| IL08 | Shandrew Island | Adams | 400414N | 0912829W |
| IL14 | Sheehan Island | La Salle | 411925N | 0885346W |
| IL08 | Shuck Island | Pike | 394245N | 0912028W |
| IL15 | Simmons Island | Cook | 415516N | 0873746W |
| IL05 | Sixmile Island | Calhoun | 385832N | 0903325W |
| IL14 | Skinner Island | Grundy | 412320N | 0881527W |
| IL04 | Skinney Island | Madison | 385220N | 0900903W |
| IL14 | Smith Islands | Will | 411248N | 0880157W |
| IL12 | Smiths Island | Rock Island | 412808N | 0903543W |
| IL09 | Snicarte Island | Mason | 400851N | 0901210W |
| IL08 | South Fritz Island | Pike | 393100N | 0910445W |
| IL04 | Spar Island | Greene | 392428N | 0903655W |
| IL15 | Spiers Island | Kane | 414608N | 0881833W |
| IL08 | Spring Lake Island | Pike | 392842N | 0905826W |
| IL05 | Squaw Island | Calhoun | 385625N | 0902927W |
| IL15 | Stolp Island | Kane | 414529N | 0881852W |
| IL11 | Sturgeon Island | Fulton | 402947N | 0895308W |
| IL09 | Sugar Creek Island | Cass | 400535N | 0902323W |
| IL14 | Sugar Island | Grundy | 412042N | 0882825W |
| IL14 | Sugar Island | Kankakee | 410054N | 0874945W |
| IL13 | Sumner Island | Winnebago | 421928N | 0892321W |
| IL13 | Sweeney Islands | Carroll | 420713N | 0900941W |
| IL01 | Swiftsure Towhead | Union | 372209N | 0892503W |
| IL12 | Sylvan Island | Rock Island | 413046N | 0903209W |
| IL08 | Taylor Island | Pike | 393655N | 0911243W |
| IL10 | Taylor Island | Hancock | 401605N | 0912907W |
| IL08 | Teal Island | Adams | 395948N | 0912741W |
| IL04 | Tip Island | Greene | 391114N | 0903533W |
| IL05 | Tisdel Towhead | Calhoun | 391642N | 0904540W |
| IL08 | Tower Island | Pike | 394204N | 0911925W |
| IL08 | Towhead Island | Pike | 394457N | 0912134W |
| IL08 | Towhead Island | Pike | 394457N | 0912135W |
| IL14 | Treat Island | Will | 412618N | 0881008W |
| IL08 | Tully Island | Adams | 401052N | 0913025W |
| IL02 | Turkey Island | White | 380644N | 0875851W |
| IL12 | Turkey Island | Rock Island | 412836N | 0903554W |
| IL10 | Turkey Island | Henderson | 404056N | 0910621W |
| IL05 | Turner Island | Calhoun | 390306N | 0904222W |
| IL08 | Turtle Island | Pike | 394442N | 0912155W |
| IL04 | Twelvemile Island | Jersey | 390244N | 0903451W |
| IL04 | Twin Islands | Greene | 392258N | 0903711W |
| IL10 | Twomile Island | Henderson | 404408N | 0910519W |
| IL14 | Vails Island | Kankakee | 410947N | 0873652W |
| IL01 | Vancill Towhead | Union | 372815N | 0892805W |
| IL12 | Vandruff Island | Rock Island | 412736N | 0903406W |
| IL04 | Walkers Island | Madison | 384129N | 0900439W |
| IL08 | Ward Island | Adams | 395238N | 0912621W |
| IL04 | Weson Island | Greene | 392845N | 0903547W |
| IL08 | White Island | Adams | 401004N | 0913031W |
| IL01 | Wilkinson Island | Jackson | 374446N | 0893724W |
| IL08 | Willow Bar Island | Pike | 393200N | 0910442W |
| IL12 | Willow Bar Island | Mercer | 410424N | 0905637W |
| IL14 | Willow Island | Kankakee | 411141N | 0875814W |
| IL12 | Willow Island | Rock Island | 412054N | 0910359W |
| IL05 | Willow Island | Calhoun | 390330N | 0904211W |
| IL04 | Willow Island | Greene | 391644N | 0903615W |
| IL13 | Willow Island | Whiteside | 415017N | 0901039W |
| IL08 | Willow Island | Adams | 395952N | 0912802W |
| IL08 | Willow Island | Pike | 393214N | 0910507W |
| IL03 | Wilsons Island | Morgan | 395103N | 0903447W |
| IL04 | Wing Island | Greene | 392439N | 0903705W |
| IL12 | Winnebago Island | Rock Island | 413209N | 0902636W |
| IL03 | Wirth Island | St. Clair | 381504N | 0895407W |
| IL15 | Wooded Island | Cook | 414704N | 0873457W |
| IL13 | Woodruffs Island | Carroll | 415719N | 0900940W |
