When I was taught about this stuff in high school (early 90’s) that’s the way it was described in the class - not looking for some kind of single source but taking into account the entire watershed that contributes to the river. Thus, the source of the Mississippi is practically half the United States.
Or is the original question perhaps a legal one? I could see a law that refers to a specific river. In that case, I suppose a scientific definition of the watershed would not be as useful as a legal definition of the rivers and their sources that way.
Geographic distinctions are subjective. That’s the answer, really.
How many Great Lakes are there? Five, right? Well, what makes Michigan and Huron a different lake? Nothing, really. So are there four Great Lakes or five? If you think Michigan and Huron are different just because it look that way on a map, why isn’t Georgian Bay a lake, instead of pat of Huron?
Why is Hudson Bay a bay and not a sea? Why is the North Sea a sea and not a bay? Why is the Bay of Biscay a bay? Why is the Gulf of Mexico not a sea or a bay?
Why do people say Europe and Asia are different continents?
The same attitude that let the Olympic committee pick a design with five rings for the continents, assigning North and South America a single ring while Europe and Asia are each given separate rings.
People are odd and the choices they make are odder, still.
Exactly. It’s a totally arbitrary distinction, like calling Huron and Michigan different lakes, but not Georgian Bay. Or why we don’t have a Baltic Gulf.
Yes. Because the definition of continent has changed drastically from its origin in classical times (as has the definition of planet, which causes similar problems). Originally the continents were defined in relation to the Mediterranean, with the breaks between them defined by the Straits of Gibraltar, the Dardanelles/Black Sea, and Red Sea. It wasn’t important that Europe and Asia met at the far shore of the Black Sea, and people had no real idea of the extent of Asia or Africa.
When the Americas, Australia, and Antarctica were discovered the term continent was extended to them, but Europe and Asia were grandfathered in as separate continents. According to some classifications, the Americas form a single continent, while in others North and South America are regarded as separate.
Just want to note that these images are how the rivers appear today, not 3+ centuries ago. All these rivers and their tributaries have been fairly heavily modified with levees, dams, and other water control devices, so it’s quite possible that the relative flows may have been different back then.
I checked George R Stewart’s Names on the Land and found that Jolliet and Marquette called the Missouri, the Pekitanoui (meaning “muddy”), and the Ohio, the Ouaboukigou (possibly meaning “shining white”). The latter was first shortened to Ouabache and then Anglicized to Wabash. After it was found to be the same river named Ohio upstream, the name was then somehow applied to a tributary.
They recorded the names of several tribes reported to live upstream on the Pekitanoui, among them: Messouri, Ouchage, Maha, Kansa, and Ouaouiatonon. These names, after varying amounts of modification, survive as Missouri, Osage, Omaha, Kansas, and Iowa, respectively.
Why would anyone, on seeing the Ohio-Mississippi confluence, call the Ohio “shining white”? It’s brown, brown, brown, in very stark contrast to the Mississippi, and visibly so even well downstream of the confluence.
That part likely didn’t change much. It’s a broad but very shallow river, and before the advent of big locks and dams was only navigable in parts, at least with anything without a particularly shallow draft. I understand they once almost exclusively used rafts on it. it’s pretty muddy by nature.
Although, come to think of it, the locals who gave it the name might have been referring to the shallows, which are (well, were) often scoured to to the rocks and tended to glisten, according to some old accounts I’ve read. Dunno, just a thought. The name used by a particularly tribe, even assuming the translation is accurate, is not going to be easily explicable.
