Mike,
I have good news and bad news.
The good news is that all of my older Mexican maps agree with your specified
location for the CHNMSO
tripoint, and there are roads very near it on both sides of MXUS.
The bad news is that all of my newer Mexican maps show the CHSO boundary almost
totally revised, with the tripoint now about 7 km east of that location, well
within the mountains and relatively inaccessible. This is confirmed by the
"Mapa Digital de México"
http://tinyurl.com/6q8kz and by "Información
Topográfica Digital" at
http://tinyurl.com/ix8y , both from the Instituto
Nacional de Estadística, Geografia e Informática.
Approximately the northern 12 km of the revised CHSO boundary consists of a
geodesic line running approximately south-southwest from the new tripoint on
MSUS. By careful measurement and comparison of the Mexican digital maps cited
above with the 1983 USGS maps and (more usefully) the 1998 UGSG aerial photos at
TerraServer, I have narrowed down the new tripoint to a certain mountain ridge
that just happens to host MXUS Monument 65 at the top of the Continental Divide!
I have found no text description of the new CHSO boundary. In fact, the
majority of Mexican state constitutions say something like "The territory of the
state consists of all land properly belonging to it and over which it exercises
jurisdiction." Mexico being relatively more centralized than the typical
federative union, the task of sorting things out has largely fallen to the
federal bureaucracy, which has historically treated such matters with benign
neglect. It has not helped that state boundaries often run through areas
relatively devoid of persons and economic importance. It is my impression that
the drive for fair elections in recent years has forced the resolution of these
issues and has finally brought delimitation to state boundaries--at least
digitally.
I cannot say with any certainty that the northern terminus of the northernmost
geodesic segment of the CHSO boundary is intended to be MXUS Monument 65 on the
Continental Divide. However, that is my tentative guess, and I consider it a
reasonable assumption. What better reason would there be for the line to land
on exactly that ridge?
If you're still interested in access, I will recommend the aerial photo at
http://tinyurl.com/54dh7 . It shows a dirt road (which might or might not be
public) across the top in the USA and Mexico highway 2 snaking across the
bottom. The latter is a paved federal highway, built since the 1983 topos. It
lies within a mile of the MXUS boundary. You'll have to switch back and forth
between the aerials and the topos (using the tabs at the upper right) and zoom
in and out (using the scale at the upper left of the image) to explore the area.
Lowell G. McManus
Leesville, Louisiana, USA
----- Original Message -----
From: "aletheiak" <aletheiak@...>
To: <BoundaryPoint@yahoogroups.com>
Sent: Friday, December 03, 2004 12:21 PM
Subject: [BoundaryPoint] chnmso
>
>
> surprisingly
> both the 24k & 100k scale usgs topos at topozone
> both dated 1983
> show a mxus2chnmso tristate point about 12 miles east of aznmso
> between features or populated places named los lamentos on the sonora
> side & el valle on the chihuahua side
>
> so does anyone have any reason to believe that this is an accurate
> depiction of the tripoint location
> based on authoritative information
>
> or any better reason to believe in a different location
>
> or does anyone know where the authoritative & current data for this
> point can be found