No one said this was going to be easy

February 14, 2017 7:01 AM

It isn't easy to determine the source of a river.

Bonus: Finding the source of the Mekong River.

posted by Literaryhero (7 comments total)

Interesting read! I know they sort of addressed this in the article, but for river conservation purposes, it seems more useful to be able to clearly define the whole watershed and protect it, rather than know for absolute certain which tributary is the longest! "Source" feels like an old time Explorer type concept.
posted by Secretariat at 8:26 AM on February 14, 2017 [1 favorite]

Good story. Back in 2001 a friend of mine published a book about traveling the length of the James River in Virginia. He started literally at the source -- iirc, a trickle of water on a hillside behind a barn in NW Virginia -- walked alongside it, and as soon as it was deep enough, paddled a canoe the rest of the way.
posted by martin q blank at 12:13 PM on February 14, 2017

Interestingly, the Colorado river above the confluence of the Green and Gunnison rivers was formerly named the Grand River (among others), before an act of congress changed it. It is at this point that it runs along the base of the Grand Mesa through the Grand Valley.
posted by Pogo_Fuzzybutt at 12:40 PM on February 14, 2017

A while back I was looking into the path the Mississippi River takes through Minnesota and it seems dangerously arbitrary what exactly is and is not the Mississippi among the many streams and lakes near its source. In fact, looking back at the history of determining the Mississippi's source in the 1800s there were many competing candidates and the one that was finally settled on used the best-guess techniques talked about in the article and as such isn't particularly definitive.

It has a nice carved wooden marker, though.
posted by Mr.Encyclopedia at 8:51 PM on February 14, 2017

The Mississippi's source is rather important because it is part of the 1783 Treaty of Paris separating the US from Canada. At the time nobody knew the source and the map they were going off of covered up the area anyway, so the treaty describes the border as a line heading due west from the northwest corner of the Lake of the Woods until it crosses the Mississippi, so being able to trace the Mississippi back at least until it crosses that line is important in defining the borders of the United States.

Of course, it turns out that the Mississippi never crosses that line, so to sort things out we've got the Northwest Angle now.

And further, Lake Itasca, the official starting point of the Mississippi, is by neither of the standards mentioned in the article the actual headwaters of the Mississippi. The branch through the Missouri River is longer, and the branch through the Ohio River contributes more water.
posted by ckape at 11:03 PM on February 14, 2017 [7 favorites]

Ok, that is fantastic, ckape.
posted by Literaryhero at 12:01 AM on February 15, 2017

Does knowing the "true" source of a river really matter?

It does. The precise location of the source is helpful for planning the management of the river and developing effective ways to protect the environment of the source regions, Shaochuang says.

I do not feel this is a satisfying explanation.
posted by polecat at 1:48 PM on February 15, 2017