It should be noted that that portion of the Oklahoma Panhandle, Cimarron County, Oklahoma has as its official history, the book, “Not a Stoplight in the County.” And in that history it points out the county seat Boise City (pronounced Boys), roughly 20 miles from the New Mexico state line, can claim the distinction of being the only American town to have been bombed by the American air force during World War II.
It was an accident, sure, but it is an interesting distinction.
Examining the NM-TX border, I notice that it doesn’t actually go north-south. Or perhaps I should say that the surveyors really did a bad job of it. The southernmost point of that border section is significantly further west than the northern point.
I’m somewhat surprised that the nominal location of that section is on a Greenwich-based meridian. Most other N-S borders in the west are on meridians measured from the Naval Observatory in Washington DC. So they’re displaced 7 minutes (I think) west of Greenwich-based meridian lines. (The exception is the CA-NV line which is on 120 degrees west of Greenwich.) I’d always assumed the NM-TX line was the same.
Not really odd if you look at the street view - it ends at the gate where you have to pay admission, or just beyond it. The gate attendant may have let them drive a little ways past to turn around. Perhaps the monument staff didn’t want them to take the pictures. More likely than the street view driver being too cheap to pay $3 admission.
Yes, sorry to resuscitate this old thread, but I have a partial answer, I believe, for this question. In 1819, the United States reached agreement with Spain on the common border between the two in North America (the Adams-Onis Treaty). This treaty specifically utilized longitudes measured from Greenwich in its descriptions. Thus, one such border was at 100º W Longitude, which was the border between the Red River and the Arkansas River.
Presumably, when the Compromise of 1850 was put together, since one side of the Panhandle was delineated by the old Adams-Onis Treaty boundary, the other side was delineated by Greenwich-based longitude, not Washington, D.C.-based longitude.
As it turns out, I believe the border as surveyed is essentially consistent with a measurement based upon Washington, D.C.-based longitude (the offset is almost identical to the offset in North Dakota’s western boundary, which is intentionally set based on Washington, D.C.-based longitude). I’ll see if I can find out if this is true, but I bet the surveyors based their survey on Washington, D.C.
Or, as it turns out, not really.
Here’s a summary of a story about how the line ended up so badly surveyed. And yes, it runs in a not-quite north to south direction. And yes, Congress did end up ratifying the boundary as surveyed, made admission of New Mexico as a state in 1912 conditional upon acceptance by that state of the boundary.
I don’t think I’ve ever seen a thread necromanced to answer a point I made. I guess I should be honored or something. I’ll admit I’d totally forgotten about it. Thanks for the update.
The Michigan-Ohio border also has a odd non parallel section. The original border was farther south (and not aligned with the Indiana border). The Toledo War resulted in the Toledo strip changing hands and the border redrawn
Interestingly, that re-drawn border does not follow a specific parallel of latitude. It was originally intended that the border run directly East-West along a parallel that intersected the southernmost point of Lake Michigan. But that parallel was thought to be further north than it actually is. When the Ohio Constitution was adopted and sent to Congress for approval, the border had been modified to run along a line extending from the point of the northern cape of the Maumee Bay to the point of the southernmost extension of Lake Michigan (said line to be used ONLY if it turned out that the Lake Michigan point was south of the said Maumee Bay point).
When the so-called Toledo War was settled in Congress in favor of Ohio, the result was a border that runs slightly to the south of west as you head west from Toledo. At the point it hits the eastern boundary of Indiana, further chaos ensues, because Indiana’s enabling act defines the northern boundary of the state to run due east from a point 10 miles north of the southernmost point of Lake Michigan until it intersects the meridian that the border with Ohio is on. So Indiana “stole” ten miles of land from Michigan with its enabling act. Unlike the Toledo Strip, this border was never in doubt; it was surveyed in 1827 and wooden posts were driven to mark it. Since it didn’t contain a major port on a commercially important lake, Michigan wasn’t particularly worried about that fact. 
(ETA)I should add that the border between Indiana and Michigan had NEVER been re-surveyed over the years since 1827. Michigan and Indiana have a joint border commission which is in the process of re-surveying the line. Given the fact it’s a generally straight line across flat land, I doubt that they will find as many discrepancies as North Carolina and South Carolina found in re-surveying THEIR boundary the last few years.
Here is another odd boundary. Generally when a boundary is defined by a river, it is the center of the channel that is the actual border. But the boundary between Delaware and New Jersey is the NJ shore of the Delaware River. I assume it is the high tide line, since the Delaware is tidal there. But then someone dredging the river extended the land on the NJ into the river and now there is a small area (less than a square mile, I believe, of Delaware on the NJ side of the river. No one lives there. Not yet, anyway. See:Learn About A Part Of Delaware In New Jersey With A Unique Past
The history channel did a miniseries specifically about how/why the states got their shapes.
Here’s a link to the series’ homepage: http://www.history.com/shows/how-the-states-got-their-shapes
ISTR a lot of the oddness in shapes and size disparities arose from gold discoveries and a desire to make the various groups of less-desirable* citizens another states problem.
*gold miners, Mormons, ‘indian’ reservations, etc… Basically, the folks that were too different for their neighbors’ to be comfortable.
That’s not the only place where a river boundary doesn’t go through the middle. The Patomac is all part of Maryland.
Another not quite so straight boundary is the southern boundary of Delaware. I assume it was meant to go due east-west, but if you look closely, you’ll see it actually goes a bit northwest as you move inward from the coast. I ascribe this to low-quality 17th or 18th century surveying.
A tv show by the same name ran for a little while, it was good and informative.
This may be 7 years too late, but as a resident of Saskatchewan I am deeply offended by this post. 
There is also a smaller piece of Delaware on the NJ side of the River south of there. It’s cut off from New Jersey by the famous Twelve-Mile Circle, the area around New Castle that was granted to the Delaware colony by Charles II. South of the Circle, the border along the river reverts to the usual mid-river line.
It was intended to go directly West from what was mis-described as Cape Henlopen at the time (a map was wrong in nomenclature). As it turns out, there is a difference in latitude of about 36 seconds between the ends of the line.
The western border of Delaware is famously a tangent line, drawn from the midpoint of the Transpeninsular line (the southern border of Delaware extended) to the Twelve-Mile Circle. What gets REALLY funny is that, at the point of tangency, the border then has a VERY small curved portion, which then straightens out to going straight north to the southern border of Pennsylvania. Then Delaware’s border heads East to the Twelve-Mile Circle, where it then arcs around to the New Jersey shore of the Delaware River. What in the WORLD Charles II and his advisers were smoking when they thought up this border in response to the request of William Penn for a colonial grant north of the Baltimore holdings and not interfering with his brother James’ holdings in what became Delaware, God alone knows. :eek:
The boundary between New York and New Jersey is defined in this manner, down the middle of the Hudson River, except that all the islands in the river are in New York. Ellis Island became the subject of a border dispute between the two states. The island was enlarged with landfill when it became the now famous immigration entry station. New York said the island was wholly theirs, New Jersey said not so fast. The Supreme Court finally ruled in 1998 that the original island was indeed New York, but all the added areas were New Jersey.
You must not have ever been to the area in question. It is basically flat with no rivers and no mountains. Sorry