▁a ▁century ▁prior ▁to ▁the ▁organization ▁of ▁the ▁Minnesota ▁Territ ory ▁in ▁ 1 8 4 9 , ▁the ▁name ▁St . ▁Pierre ▁( St . ▁Peter ) ▁had ▁been ▁generally ▁applied ▁to ▁the ▁river ▁by ▁French ▁and ▁English ▁expl or ers ▁and ▁writers . ▁ ▁Minnesota ▁River ▁is ▁shown ▁on ▁the ▁ 1 7 5 7 ▁edition ▁of ▁Mitchell ▁Map ▁as ▁" O u ade b amen i ſ s out é ▁[ W at p á ▁M ní s ota ] ▁or ▁R . ▁St . ▁Peter ". ▁ ▁On ▁June ▁ 1 9 , ▁ 1 8 5 2 , ▁acting ▁upon ▁a ▁request ▁from ▁the ▁Minnesota ▁territorial ▁legisl ature , ▁the ▁United ▁States ▁Congress ▁decre ed ▁the ▁ab original ▁name ▁for ▁the ▁river , ▁Minnesota , ▁to ▁be ▁the ▁river ’ s ▁official ▁name ▁and ▁ordered ▁all ▁ag encies ▁of ▁the ▁federal ▁government ▁to ▁use ▁that ▁name ▁when ▁referencing ▁it . ▁ ▁The ▁valley ▁that ▁the ▁Minnesota ▁River ▁flows ▁in ▁is ▁up ▁to ▁five ▁miles ▁( 8   km ) ▁wide ▁and ▁ 2 5 0   fe et ▁( 8 0   m ) ▁deep . ▁It ▁was ▁car ved ▁into ▁the ▁landscape ▁by ▁the ▁massive ▁gla cial ▁River ▁Warren ▁between ▁ 1 1 , 7 0 0 ▁and ▁ 9 , 4 0 0 ▁years ▁ago ▁at ▁the ▁end ▁of ▁the ▁last ▁ice ▁age ▁in ▁North ▁America . ▁ ▁Pierre - Char les ▁Le ▁Sue ur ▁was ▁the ▁first ▁European ▁known ▁to ▁have ▁tra ve led ▁along