New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1873-08-23
WESTERN EXPLORATIONS.

sURvEYs-IN THE HEART OF THE hoONi
NOTWITHSTANDING NAMELEsS -,
THIRTEEN THOUSAND FEET IN HUH
AMONG THE LIMESTONE ROCKS.
IrRoM OCCASIONAL CORRESPONDENT or I'M -. o.,
CAMP FAST RIVER near Grand Ieocal' Coi'
Aug 4-Since last reported the uo'neo % wy
yey we have been ont of reach OF post-onlces anu
na;, ro,.os aud II ia only the accident OF the de-
partnra Of one of orr party, who takes the BACK
track tovor civilization in day or two that gives
ma the o,nortnnity TO send further account. we
are now on one of the numerous tines as they may
he called of the east fork of the East RIVER d
hranob ~ the Gunnison, whose waters finally reach
the Pacific Ocean through the great western Colo
RADIO So much by way of preliminary dehhlooh
ef position no one eau find our position on any map
that has yet been made but it will be better under
stood what place we occupy when l have told how
we have reached it, My last letter was dated from
the Twin Lakes on the eastern or Atlantic slope OF
the central range We first moved up about twelve
miles to the forks of the little river that gushes
through the Lakes, or into the very heart of the
range, and the main camp lay quiet there few
DAYS. while detached parties explored the country.
Two great SUBMITS were assembled from that sta
ton. The first was immense rounded peak OF
granite full 1900 feet bigh that lowered directly
above the camp aud of which the last 2ocO ieet nau
10 be done by sheer scramblng over broken rocAs'
without help from horse or mule. IL was canou'
provisionaly La Plata Peak, from the Vaiiey oeloW
=, md the silver mines i'm its netghborhood. Inc
lew which il afforded of the gorges, the COMBS tine
snphitheaters the peaks the valleys the riyuiets'
INC little lakes of the range was not to be sur
assed You must understand that this climbing
# high peaks is BY no means for sport or dettante
work. il is an essential feature of the Typographical
art of the Survey.
MODE OF MOUNTAIN SURVEYS.
Hvou cannot 60 over every foot Of a country, re-
cording as You 60 there is other way IN which II
can be so commanded and understood as by looking
down on it from above. The typographical party
usually leave the main the afternoon before an
ascent and make camp OF their own at the IlnDer-
line as close as possible to the summit Then
timely start and rapid climb the next morning put
chem on the top at early hour, and they work TIL
lust time enough is left TO get back to camp atnght
BY grddieHter the angles to all the principal points
near and far are taken with the horizontal angles
for positions and the angles of depression for alt-
tide A detailed Typographical sketch, by lines of
equal altitude is made of the country within reach
and is Joined on or Tapped over by similar sketch
made at the next station. The drainage lines are
carefully traced out. And the artist makes piano.
ramic view either of the whole scene, or of such
parts of it as have special importance bringing out
the mountain and valley forms with the talthtuness
and more than the distinctness Of photograph
Our artist, Mr.. Holmes, has been pronounced by
high authority the best scientific craftsman IN the
country, and his sketches typographical geoOgi-
cal are certainly extraordinary for their vivid
faithfulness to nature. BY this system Of observa-
ton and record carried carefully district its
topography is more fully understood and more accu-
rately laid down than is possible in any other way
without the expenditure of vastly more time and
labor, and from it will come forth map far supe-
nor TO those that we have of any of our Eastern
States and answering all the purposes of the geolo
gist and the explorer for long time to come OF fol
always
IN THE HEART oP THE ROCKY MOUNTAINS.
And if there is anywhere in the country region
calling for such treatment, and calculated to Illus
trate the excellence of the system surely it is this.
The very heart of the Rocky Mountains, the grand
ess upft of the continent is here. This very range
on which we were, of sharp definition and unswerv-
ing direction. running nearly north and south for
about a hundred miles, broken into peaks which
range, with wonderful uniformity, between 1905
and 1880 feet, TO be the eliminating point OF
the forces that have built the continent ana better
entitled than any other to the title of Sierra Madre
mother range" which has sometimes been applied
toit So far as the explorations OF the survey have
vet extended it is composed entirely of granite anC
ernptive rocks; the sedimentary beds which we left
N H..
this side of the head waters of the Colorado The
range is most splendidly seen from the eastward
from Lincoln or Buffalo across the Arkansas Valley
which runs along its whole eastern flank. It's north
ernmost point is the Mountain of the Holy Cross, OF
which have spoken before as being the one which
when we visit it by and by, we rather expect TO ind
the highest Of all IL is broken on its eastern slope
by many deep and penetrating ravines which for
mery sent down great glaciers into the valley, as
attested by the vast mOranes still existing OF the
western side will speak presently. when come to
tell of our journey that way for the other peak we
assembled from the camp at the Forks was too re-
markable not TO call for few words of description
THE FIRST MOUNTAIN ENTIRELY OF VOLCANIC ROCK.
II was the first mountain composed entirely OF
eptve OF volcanic rock that we had fallen in with.
Contact between the granite and the eruptve we
found in many places within reach OF our camp, and
the tracing Of the relations of the two formations
constitutes great part Of the geologic interest Of
,he locality Here, however, was heightened
amphitheater or mountain valley, with steep, craggy
sides and a broad green bottom of which the sur
rounding ridges were wholly of volcanic material
rising at the further end INTO two most rugged sum-
nits. of about 1900 and 1850 feet respectively
The higher. which we climbed by a difficult ascent
through crumbly material that gave no secure foot
old was the most savage mountain top lever stood
upon; a mere comb OF blacklist rock, split with lis
cures that went down thousand feet perpendicular
toward the head of the valley. On the other side
and about 5000 feet directly below us. was branch
of the Roaring Fork of the Grand River, run
ming northward through narrow ravine
which split the range, parallel with its
axis, for many miles before winding out TO
the west. softer streak close by, in the varying
volcanic material, gave line Of scori9-like debris
clear down TO the valley, down which one could
have plunged ankle-deep in half an hour; and be-
yond it, again, was hard layer that gave rugged