One thing that is not true of the Mississippi-Missouri River system is that it became famous during the gold-rush days in Alaska.
The system of rivers that involves the Mississippi and the Missouri Rivers is the largest river system in the United States and it has a drainage basin that is so large that it covers most of the central plain of the United States.
The Mississippi-Missouri River system is based in mainland United States however and does not extend to Alaska and so could not be famous as a result of a gold-rush in Alaska.
Find out more on the Mississippi-Missouri River system at https://brainly.com/question/13220307
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