How are the headwaters of a river determined or defined?
I am originally from MN and always thought it curious that Lake Itasca could be the source of the Mississippi River. It is neither the highest point in the watershed nor the furthest distance from the delta. I know that determining the headwaters had great significance for explorers (Nile, Amazon, Mississippi) and in the case of the Mississippi, it even settled a border dispute between MN, MB, and ON. I even asked my geology professor when I was in college, but he couldn’t provide a satisfactory answer. I’m hoping I’ll finally get a good explanation. Thank you.
