ON PREPARATION OF MEXICO LIST
In October 2004 I completed a project to list the
50 most prominent Mountains of Mexico. The list is
found at the bottom of this email, and at
This write up discussed several aspects of this
Possible biological islands
List preparation and errors
For more info on prominence see www.cohp.org or
- Andy Martin,
I. Climbing Challenges
Eight of the listed peaks are described in Kelsey's
World Mountains guide: (number is position on
( 1) Orizaba
( 2) Popo
( 3) Colima
( 4) Toluca
( 7) Diablo
( 9) Malinche
Another peak that may be known to climbers is (10)
Sierra la Laguna.
Bob Packard Robert.Packard@nau.edu has climbed
(19) Virgenes and (37) Sandia in Baja, making him
climber of these peaks to the best of my knowledge.
This leaves about 40 peaks that are unknown to most
hikers on the planet. The most exciting part of this
project was looking at big peaks formerly unknown to
and plotting out potential routes to the summit.
One that looks difficult is (26) Sierra el Cerro
Azul, a possible
ultra at 4,921+ 131. This summit is isolated, has
steep flanks, and
probably is covered by dense vegetation, as it lies
There are also some challenging desert peaks near
that appear to require 5,000 feet vertical gain while
bush wacking up rugged limestone terrain. The
Monterrey region boasts
the densest cluster of peaks on this list, claiming
of the 50 within 75 miles of the city. Monterrey is
perhaps 300 miles from San Antonio Texas, and thus
Texans are the best situated to explore big
peaks in Mexico.
On the opposite extreme of difficulty, the
named (25) Volcan de Tequila near Guadalajara has a
access road to top.
It is interesting for me to contemplate the "future"
of this list. The high point list of the 32 Mexican
(16 have big prominence) was published in 1991 and
little interest to date. Hopefully this new list
will have at least
one climber tackle it in the next decade.
II. Peak Distribution
Plotting the first fourteen peaks listed (these have
identifies four major areas with big peaks.
The most striking is a belt of 5 big volcanos
from coast to coast through Mexico City. From west
they are (3) Colima, (4) Toluca, (2) Popo, (9)
Malinche and (1) Orizaba.
Just south of this following the coastline are 3 big
peaks (8) Conchas, (5) Tiotepec, and (6)
Near Monterrey are (11) Madera, (12) Chena, and (14)
Rafael/Morro is over 12,000 feet high and has great
"isolation", being over 300 miles from any other
reaching this height.
Baja is anchored at the top by (6) Diablo and bottom
by (10) Laguna.
One surprise is the lack of big peaks in NW Mexico,
This part of Mexico is made up of Sonora,
Chihuahua and Sinaloa, and is a rugged land with
over 9,000' elevation and big canyons. However, it
little in the way of big prominence, with only the
known (49) Sierra Alamos and even lesser known (43)
Los Algodones making the top 50 cut of 4,265 feet
By comparison, Arizona has 9 peaks that surpass this
III. Possible Biological Islands
Prominence is a useful tool to identify biological
with plants and animals isolated on high ground that
on all sides by much lower terrain. Often these areas
harbor unique species.
Other factors that we look for here are peaks with
areas of high ground, as opposed to a sharp summit.
We expect peaks surrounded by large rivers or even
to have more biological isolation. Finally, peaks
have tops far above timber line, perhaps even
will not have as many species living near the summit.
Taking these factors into consideration and looking
at the top ten peaks listed, possible biological
Picacho del Diablo, in northern Baja.
A large area of high ground lies
to the west of the peak.
Cerro las Conchas
HP Sierra la Laguna, at tip of Baja, and surrounded
on 3 sides. Known to have unique
IV. List Preparation and Errors
The University of Arizona has a very good collection
1:50,000 scale maps for all of Mexico. I relied on
for elevation and naming information. These were
prepared by the Mexican mapping agency in the 1970s
1980s time period. They normally use 20 meter
in mountain areas, and 10 meters in flat lying
I have found them to be fairly accurate on a few
hikes south of the border, though they can "hide"
bothersome cliffs in some cases.
Road info on these maps is not always reliable.
Mexican place names seem to be somewhat variable,
and it is unknown if the names found on the 1:50K
maps are the most authoritative.
My biggest problem with these maps was the lack
of spot elevations. Most do not have a single spot
or benchmark elevation on the quad, but only labels
on the 100 meter index contours. Sometimes
the 100 meter labels are incorrect, which of course
The lack of spot elevations on peaks or saddles
means that most prominence values fall into 20
meter (65.6 feet) "brackets". This leads to lots
of ties of course, and helps explain why six
peaks below the top 50 cut off are still possible
members of the top 50 set. Note that saddle
are not listed, but can be computed by subtracting
prominence from summit elevation. For example,
on Popo we have:
- prom: 9908+ 131
This means the Popo saddle lies up to 20 meters under
the 2380 contour shown on the 1:50K map. The summit
an minimum elevation of 5400 meters, with up to 20
meters additional height. The minimum prominence
is 3020 meters, with up to 40 additional meters
While the 1:50K maps were essential to provide
peak information, I also relied on the 1:500,000
Defense Mapping Agency Aerospace maps purchased from
My set dates from the mid 1980s, and was used in
which peaks might have 4,000' prominence, and thus
further checking on the Mexican quads. These air
have elevations given for summits, but these values
differed widely from the 1:50K values. Usually they
higher, as you would expect on air maps. However,
on (31) Zamorano, the air map (TPC J-24B) shows
and the Mexican map has 11,023+ 66. Hopefully pilots
using the air map elevation in the vicinity of
are flying extra rugged aircraft ;)
This same air map shows a major river flowing up and
over an important saddle just south of lake San
Allende, 40 miles west of Zamorano. The Mexican
topos do a much
better job here, showing the river flowing through
a canyon, and relocating the saddle to the world of
Users of my Mexican State HP list will note that in
a greater reliance was placed on air map elevations.
a lot of quads were scrutinized since then.
In a list of this sort my main concern is that a peak
was accidentally left off, due either to a glitch in
air maps, or inadequate screening on my part. It
would not surprise me to learn that a peak or two
was not listed. However, Jonathan deFerranti has
computer program processing SRTM data to
list almost 40 of the peaks, without detecting an
In the future he plans to list peak in Mexico down to
2,000' prominence, which will allow a complete double
Finally, those interested in an "eyeball bender"
can try to find the key saddle 5,052- (66) for peak
(40) Cerro Tzontehuitz on quad E15D84.
The flat lying karst terrain makes this a challenge.