7MB PDF - Association for Mexican Cave Studies

SOTANO DE LAS COYOTAS
During the month of April 1982,
members of the Sociedad Mexicana de
Exploraciones Subterraneas set out to
explore a new cave area in extreme
northeastern Guanajuato. The
Mirasoles area is in the Sierra Gorda
de Guanajuato, part of the Sierra
Madre Oriental. This area was located
due to its proximity to the La
Florida, Queretaro area, where we had
been conducting photogeologic and
speleological studies. During this
first trip we explored forty new
s6tanos, including S6tano de las
Coyotas, 581 meters deep, S6tano de
las Hoyas, -282 meters, S6tano de las
Coyotas No.2, -160 meters, and
S6tano de Odi16n, 92 meters deep.
Access to the area is from the
town of San Ciro de Acosta, in the
state of San Luis Potosl, south of
Rlo Verde. It is possible to drive
to the village of Canoitas, and from
there it is a three-hour walk to the
uninhabited Hoya de Mirasoles.
Discovery of Coyotas
On the eighth of April, Maribel
Garcia, Manuel Urquiza, and I were
searching the area 3 kilometers northeast
of Hoya de Mirasoles. After
finding various small pits, we arrived
at a wide, forested dolina. At
the bottom we discovered two s6tanos
80 meters apart. The first one we
descended, S6tano de las Coyotas No.
2, had an entrance pitch of 60 meters.
We saw that it continued, but we had
run out of rope. So we went over to
the other pit, S6tano de las Coyotas.
The entrance is a fracture 8 meters
long. I descended the entrance pit,
a free drop of 30 meters, and then
Manual came down. Investigation of
a short passage led to a second drop
of 20 meters. We descended this to
a large ledge overlooking the third
drop. Since we were out of rope, we
tossed a rock to check the depth. A
deep one!
The following day Abigail
Cervantes and I returned to the pit
with over 200 meters of rope. We
Carlos Lazcano
quickly descended the first two drops
and then the huge third drop, 56
meters deep. I descended first, and
Abigail immediately after. We arrived
at a small horizontal passage 5
meters long, through which there was
a fourth pitch. This one dropped 68
meters to a small well, followed immediately
by a fifth drop that we
found to be 56 meters deep. We were
then in a passage with two beautiful
deep pools and a large flowstone mass
coming off the base of the drop.
Ahead was yet another drop, but the
rope we had brought had run out. A
rock drop indicated this pit was over
80 meters deep. Two hundred thirty
meters down and still going!
To the Bot tom
Several days passed during which
we explored other pits in the area.
On April 13, Antonio Saloma, Guillermo
Mora, Jose Antonio Paez, and I returned
to Coyotas with 700 meters of
rope. We quickly negotiated the
first five pitches and tied off a
100-meter line for the sixth. I
began the descent slowly, 10, 20, 30
meters. Soon I was at 60, 70, 80
meters, and then I was on the bottom,
at 84 meters. Now, six drops down,
I was on a 3-meter-wide ledge over
another drop. We all descended this
one, of 23 meters, and the next one,
which was 40 meters deep. This
brought us to a large room at -400
meters, the Sa16n de Susana.
The Sa16n de Susana is the only
spacious and comfortable place in the
cave, and it contains a crystal-lined
pool. The cave continues through a
meter-diameter hole in the floor, the
Hoyito Karstico. This gives access
to a succession of drops of 12, 10,
and 16 meters. Immediately after
that was another long drop 58 meters
deep. The cave then continued down
d:ops 12, 26, 28, and 5 meters deep,
wlth only very short stretches in
between. The last drop lands in a
small room in one corner of which is
a fissure that becomes too tight
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