Show Longest River The Mississippi Missouri generally general ly Jy considered one river by geographers Is U the longest in the world From the head fountain of the Missouri Mis fills in the on the southwest southwest south south- west border of Montana its total length l is miles From the source of its other branch at Lake Itasca in northern Minnesota the called so-called Mississippi proper is 2553 miles long The second longest river nver riv nv- nv er is the Nile Kile miles from its remotest headstream the which flows into Lake Victoria The Amazon river in South America has the greatest basin basin square miles |