Geography thumb|Voyageurs National Park Koochiching County lies on the northern edge of Minnesota. Its northern border abuts the south border of Canada (across the Rainy River). The Rainy River flows west-northwestward along its north border, being fed by several rivers which drain from the county into the Rainy: Rat Root River drains the east central part of the county; Little Fork River flows northward through the eastern part of the county; Big Fork River flows northward through the east-central part of the county; Black River flows northward through the central part of the county; Rapid River and East Fork Rapid River flow north-northwestward through the western part of the county, joining in the northwestern part of the county shortly before exiting the county's west line to discharge into the Rainy, just west of the county's northwestern corner.
gEoGraphy thumb|vOyAgeuRs nationAl park kooChiChIng CoUnTY Lies on the nortHeRn edge of MInNEsOta. ItS NortHeRn boRdEr abuTS thE SOuTh bordEr oF Canada (aCross the raiNy riVer). THe RAiny River fLoWS west-nORThwEstWArd aLONg its North bordeR, beinG fED by sevERAL rIveRs WHIch DRain FrOM tHe counTy IntO the rainy: rAT rOOt river dRAins the East CentRal part of tHe cOUnty; liTtle Fork riVEr FLows NOrtHWaRD thrOugh tHe eAsterN part of The counTY; BIg fOrk RivEr FlOws noRthwARd througH the East-CenTRal parT of the COUNty; BlAck river FLows NORTHwARd tHrough the CeNtRal ParT OF the county; rAPId riveR and eASt fork RAPid RIveR flow NorTh-nORThwEstwarD throUgH the wEsTern pArT Of The couNtY, JoinINg iN the nORthweSterN pArt oF the cOuntY ShorTLy before Exiting the coUNTy's WeSt LiNe TO diSchargE inTo thE RAinY, JusT west of the county's NORThWestErn COrnEr.