This is basic to the concept of “deep ecology” — that political borders should coincide with watersheds.
And that straight line continued right around the other side of the world, a few years later, dividing Asian Portuguese colonies (Macao, East Timor…) from Asian Spanish ones (Philippines).
The Colorado border doesn’t have 4 sides. It has 697.
The Four Corners Monument (where Utah, Colorado, New Mexico and Arizona meet) is off 560 feet.
Mostly due to survey inaccuracies and corrections due to our round earth.
I’m not trying to nit-pick. I just find that kind of interesting. Colorado isn’t a rectangle
Just to be pedantic, the Four Corners Monument may be off be 560 feet from it’s intended location but it is now the exact spot where the four states meet:
Finally, we cannot overemphasize the fact that the aforementioned technical geodetic details are absolutely moot when considering any question of the correctness or validity of the Four Corners monument in marking the intersection of the four states. Indeed, the monument marks the exact spot where the four states meet.“A basic tenet of boundary surveying is that once a monument has been established and accepted by the parties involved (in the case of the Four Corners monument, the parties were the four territories and the U.S. Congress), the location of the physical monument is the ultimate authority in delineating a boundary. Issues of legality trump scientific details, and the intended location of the point becomes secondary information. In surveying, monuments rule!” Why the Four Corners Monument is in Exactly the Right Place
If the kick misses the goal posts, move the goal posts and call it a score! 
We have a lot of monuments that are gone now. I totally understand that. One of our ‘monuments’ in the county I work for doing GIS was a tree. A literal tree and it was called bearing tree monument. It is long, long gone.
Another weird one is a a mine that move the top of a drainage basin. Changing it a bit. Uh… The original line for the boundary still stands though.
Hey, guys, I’ve got two mil from a shady consortium of Arizona real estate folks. Who wants a cut of it? All we have to do is move a hunk of stone…
that is a username/post combo
How do you think I got the gig?
the captain wants it back
Different Macadam but both were Scottish scientists; John Loudon MacAdam (b.1756) was the civil engineer with the eponymous paving: John Macadam (b.1827) had a short but illustrious multifaceted career in Australia and the nut was named in his honor.
I know you meant a joke but I was curious so I looked it up.
Exactly.
In surveying, “monuments” don’t rule. We don’t stop looking just because a monument was found (much to the chagrin of those paying to have surveying done). All of the available evidence is considered; physical evidence, field notes of past surveyors, plats, deeds, records of survey… then the “best available evidence” is used to determine the boundaries in question.
In Antarctica, they have a January 1st tradition of pounding the new pole marker into the ice. The ice sheet slides about 30’ a year, so they have to put a new one in every year. Sadly, there is no long line of markers marking where the axial pole used to be, because they keep picking up last year’s marker.
That is sad! That would be a cool thing to see/have mapped out, like when they set a line of stakes across a glacier so you can see how the flow speed is higher in the middle than in the friction zones on the edges…
Yes, with the year imprinted on each marker.
I do not disagree. However, I think that in the case of the Four Corners Monument, the monument is the “best available evidence.”
On a tangent. I have a couple of pieces of property where the surveys were tied to monumented (Is that a word?) section corners. Both of these monuments have now been completely obliterated.
I apologize for the hijack. We now return you to your regularly scheduled thread.
Yes! A smaller, faster analogue to the Hawaiian Islands.
Then again there’s this post of mine from over 15 years ago:
Another thing that is interesting is prescriptive rights. If you have been openly using a property for a certain number of years say for an access for a driveway, and there are no complaints, that access can’t be just cut off. This is settled in the courts.
I would recon the US/Canada border along natural features would follow the St Lawrence River, then the middle of the Great Lakes (except Lake Michigan), then at the western tip of Lake Superior jump to the Mississippi River drainage’s northern edge and follow that to the Rockies (yes, that means Canada gets northern MN and roughly the northern half of North Dakota where the Red River of the North lies). The meeting of North America’s large drainage basins is at Triple Divide Peak in Montana (where water falling on the summit may eventual find it’s way to the Atlantic, Pacific, or Arctic oceans).
Then, grab the northern boundary of the Columbia River drainage (the US would get Revelstoke and Whistler - seems like a good trade for northern MN and ND 
). And then find some other minor geographical features to follow the present-day border to ensure Vancouver BC stays in Canada and Seattle stays in the US.