▁the ▁river ▁car ries ▁the ▁name ▁it ▁does ▁today . ▁ ▁Ge ology ▁and ▁e col ogy ▁of ▁the ▁river ▁The ▁river ▁flows ▁through ▁agricult ural ▁land ▁that ▁dro ps ▁a ▁gentle ▁ ▁per ▁. ▁However , ▁the ▁river ▁does ▁contains ▁a ▁series ▁of ▁three - ledge ▁rap ids ▁near ▁its ▁mouth . ▁ ▁The ▁upper ▁ ▁of ▁the ▁river ▁have ▁lower ▁water ▁flow ▁than ▁the ▁lower ▁, ▁and ▁suffer ▁from ▁de grad ed ▁habitat . ▁In ▁the ▁late ▁summer ▁and ▁fall ▁dry ▁season , ▁much ▁of ▁the ▁upper ▁two - third s ▁of ▁the ▁river ▁d ries ▁out , ▁leaving ▁only ▁un connected ▁po ols . ▁Only ▁on ▁the ▁lower ▁third ▁is ▁sport ▁fish ing ▁allowed . ▁Minn ows ▁are ▁abund ant ▁throughout ▁the ▁river , ▁and ▁among ▁those ▁found ▁in ▁the ▁Dev ils ▁River ▁are ▁the ▁western ▁black n ose ▁d ace , ▁common ▁cre ek ▁ch ub , ▁common ▁sh iner , ▁long n ose ▁d ace , ▁northern ▁re db elly ▁d ace , ▁red side ▁d ace , ▁white ▁su cker , ▁and ▁various ▁species ▁of ▁d arter . ▁Sport ▁fish ▁such ▁as ▁black ▁b ull head ▁cat fish ▁and ▁rock ▁bass ▁are ▁native ▁to ▁the ▁lower ▁third . ▁The ▁Wisconsin ▁Department ▁of ▁Natural ▁Resources ▁stock s ▁brown ▁tr out , ▁northern ▁pi ke , ▁and ▁rain bow ▁tr out ▁in ▁the ▁river , ▁but ▁over - w inter ▁surv ival ▁rates ▁are ▁very ▁low . ▁The ▁rust y ▁c ray fish , ▁an ▁invas ive ▁species ,