yst ers ▁over se as . ▁It ▁is ▁commer cially ▁f ished ▁down stream ▁of ▁the ▁R t . ▁ 8 9 ▁bridge ▁at ▁Spring ▁Valley . ▁However , ▁an ▁inf est ation ▁of ▁invas ive ▁Asian ▁Car p ▁has ▁crow ded ▁out ▁many ▁game ▁fish ▁in ▁the ▁river . ▁The ▁Illinois ▁River ▁is ▁still ▁an ▁important ▁sports ▁fish ing ▁water way ▁with ▁a ▁good ▁sau ger ▁fish ery . ▁ ▁The ▁Illinois ▁forms ▁part ▁of ▁a ▁modern ▁water way ▁that ▁connect s ▁the ▁Great ▁L akes ▁at ▁Chicago ▁to ▁the ▁Mississippi ▁River . ▁ ▁The ▁water way ▁was ▁originally ▁established ▁by ▁the ▁building ▁of ▁the ▁Illinois ▁and ▁Michigan ▁Canal ▁that ▁connected ▁the ▁Illinois ▁River ▁to ▁the ▁Chicago ▁River . ▁When ▁the ▁San it ary ▁District ▁of ▁Chicago ▁later ▁revers ed ▁the ▁flow ▁of ▁the ▁Chicago ▁River , ▁the ▁poll ution ▁and ▁se w age ▁of ▁the ▁city ▁of ▁Chicago ▁flow ed ▁down ▁into ▁the ▁Illinois ▁River . ▁The ▁Illinois ▁and ▁Michigan ▁Canal ▁has ▁since ▁been ▁replaced ▁by ▁the ▁Illinois ▁Water way , ▁including ▁the ▁Chicago ▁San it ary ▁and ▁Sh ip ▁Canal . ▁River ▁traffic ▁and ▁flo od ▁control ▁is ▁managed ▁by ▁eight ▁lo cks ▁and ▁d ams ▁operated ▁by ▁the ▁U . S . ▁Army ▁Corps ▁of ▁Engine ers . ▁As ▁of ▁ 2 0 1 1 , ▁all ▁lo cks ▁and ▁d ams ▁on ▁this ▁water way ▁are ▁closed ▁to ▁visitors ▁for ▁security ▁reasons , ▁except ▁the ▁Star ved ▁Rock ▁Vis itor ▁Center , ▁which ▁offers ▁an ▁excellent ▁interpretation ▁of