Native Americans settled along rivers for several reasons. Rivers provided water and abundant food sources, from mussels and fish to ducks and muskrats. Prehistoric people left their "dinner trash," such as bone and shell fragments. These dinner discards give archeologists insights into ancient diets. Remnants of net weights, bone fishhooks, and broken spears are clues about how people during various periods captured dinner.

Rivers were also transportation routes. The scope of prehistoric trade networks varied dramatically over time.