Finding Frémont's
Long Camp
The Long Camp was reached by the advance party on February 10, 1844 and was occupied through the 19th as the road up from Markleeville (nearly twenty miles) was constructed to get the horses and mules up the steep canyon and across the deep snow. It was the base used for explorations ahead. From the nearby peaks the Central Valley was in view to the west, and Lake Tahoe was first seen to the north east.
The latitude as given in the narrative of the Report.
These figures are wrong as printed in the narrative portion of the original edition of 1845, and they are wrong in all subsequent printings to date. They are still frequently cited and have been responsible for misplacing both the location of the camp and the point of the crossing of the pass, which the narrative gives as "38° 44'." Gianella did note the apparent misprints, and suggested the correct latitude figures, but did not determine that the determinations made by Frémont and published in the Astronomical Tables of the Report were actually correct.
And on page 484, "LONG CAMP, February 19, 1844, altitudes
of the sun...Latitude - 38° 41' 51"." Frémont's longitudes in this part of the expedition are wrong by about 24 miles because his chronometer had stopped running near Bridgeport. He had managed to restart it, and he and Preuss and Carson had sat up many long, cold hours taking double altitudes of Procyon, observing lunar occultations, and the motions of the moons of Jupiter, but the chronometer's rate of going was erratic. The reported longitudes should be disregarded, and physical features substituted for the second line of position. But, for the determination of latitude, the sun at noon
and a reasonably accurate timekeeper serve well, as does,
with the same timekeeping ability, the altitude of Polaris.
Today, Polaris is within about 1 degree of the celestial
pole. In 1844, it was about 1.5 degrees distant.
With the help of an assistant taking down his readings and recording the time of each observation from a chronometer, he made ten observations of Polaris on February 14th between 6:55 and 7:05 PM. Having the observed altitude of the star, he had then to consult a table in an Astronomical Almanac to correct for refraction, in order to obtain the true altitude. Taking the apparent time of the observation, he would consult a table of the sun's right ascension for the year, month, day, hour, minute, and second. Adding or subtracting the time value given therein converts the true altitude (39° 30' 22") to latitude (38° 41' 03"). The published tables allow us to determine that Frémont made the observations at about 7 hours Greenwhich time. He would have chosen this hour of about 11 o'clock local time because polaris was at its highest directly above the celestial pole. This was because that while the necessary correction for the position of the star relative to the pole at this time was at its greatest, the rate of change in the position of the star was at its slowest, allowing for the most accurate determination to be made if indeed, as he suspected, his time keeping was not perfect. In his journal entry for February 18th, Preuss says, "Our latitude is 38° 41'," confirming Frémont's determination of 38° 41' 03". Going to the place: Confident that both Frémont's latitude and Preuss's drawing were accurate, I determined to locate the exact site of the Long Camp. I set out on October 14, 1996 and drove to Red Lake, at the foot of Carson Pass which lies at a latitude of N38° 42'. I then turned south on Blue Lakes road for about a mile to where I had determined from a Geological Survey map that latitude 38° 41' lay.
Using a compass compensated for the local 15° east declination, I then traveled due east on the line of latitude. The elevation at Blue Lakes road is just under 8,000' El., and about one quarter mile east are three rounded hills, which are glacial moraines. As the hills are ascended, the small dark peak (9,002 El.) to the west comes slowly into view. On the north side of the hill, near the top, at an elevation of about 8,050' (cf. Frémont's 8050 feet) is Charles Preuss's vantage point - exact in every detail. The small center peak can be seen in this relationship from no other position. Compare with image at top of this page.
You can navigate on this Google®
map by dragging, zoom in/out,
or change from satellite to roadmap or terrain
imagery.
  A
report from a Long Camp site visitor.
Below, the route and the place from which the observation of polaris and the determination of latitude were made on February 14, 1844. Frémont's determination of the latitude of the Pass on February 19, 1844 ( 38° 41' 51") runs right down the present highway 88 at the top of Carson Pass. 
|
|||||||||||||||||||||||||||
This
drawing appears opposite page 234 of the printed report of
Frémont's second expedition. Frémont wrote,
"February 14, [1844]. Annexed is a view of the
dividing ridge of the Sierra, taken from this
encampment." The drawing is by Charles Preuss, the
expedition cartographer. Preuss made his drawings as records
of locations - drawings of cartographic correctness, as
opposed to artistic landscape renderings.
Frémont
gives the location of the Long Camp as,"...within two and a
half miles of the head of the hollow [leading up to
Carson Pass], and at the foot of the last mountain
ridge. Here two large trees has been set on fire, and in the
holes, where the snow had melted away, we found a
comfortable camp...The elevation of the camp, by the boiling
point, is 8,050 Feet." On page 235, in the body of the text,
the position of the camp is stated to be, "latitude
38° 41' 57", longitude 120° 25' 57"."
On
page 483 of the original Senate edition of the Report are
found Frémont's actual tables of "Astronomical
Observations." There is found, under the heading "LONG
CAMP, February 14, 1844, altitudes of Polaris...Latitude -
38° 41' 03"." The figure of 57" given in the
body of text is an obvious transposition from the erroneous
longitude figure.
Frémont
used an artificial horizon with his sextant, because, unlike
when at sea, the horizon of the earth cannot actually be
seen due to physical features - mountains, in this case. The
artificial horizon is a glass-covered box filled with
mercury. The mercury forms a level mirror, and it is the
reflection of the star, or other object that is sighted. The
resulting angle must be divided by 2. 
The
top of the hill is open on the north side, and just below
would have been Preuss's "kitchen hole" as shown in his
drawing. The low middle ground traversing the view is the
route of Blue Lakes Road - built in the middle 1850's as the
Big Trees Route connecting the Carson Route with the
southern mining districts. The large mountain to the left is
Elephant's Back. To the right, the canyon angling up at the
base of Red Lake Peak hides Highway 88 rising to Carson
Pass. The latitude is N38° 41' 03", as Frémont
and Preuss said, and the longitude is W119° 57' 19", as
determined from the Preuss drawing, using the perspective of
the small peak in the center to triangulate and the GPS
receiver to provide the numbers.
Just
northeast is a larger rounded hill (8256' el.) which was
free of trees and swept clean of snow (as when
Frémont described it in 1844) and covered with, as
then, dried bunchgrass, where the horses and mules were
grazed just before crossing the Pass. It is shown here in an
autumn photo looking southeast from Red Lake at the base of
Red Lake Peak. In the background are (L to R) Jeff Davis
Peak (9065'), The Nipple (9342'), and Deadwood Peak (9846').
Red Lake has been much enlarged by damming. It was quite
small, frozen, and covered with snow in 1844.
THE
CROSSING
Excerpts from 
