ROUTE NEAR THE FORTY-FIRST AND FORTY SECOND PARALLELS. 63 
with’s party was on this divide, about the 10th of April, the streams were not swollen, and 
they could not discover that the depth of snow (from 12 to 16 inches) was less than in winter ; 
that is, the sun had not yet begun to melt it; on the northeast slopes of the hills and ravines 
it had accumulated in deep drifts. The spring freshets of Weber and Timpanogos rivers are 
six feet in height. 
Captain Stansbury says that the Uinta mountains were covered with snow for a consider- 
able distance from their summits on the 19th of August, 1849. The following extracts from 
his report may give an idea of the severity of the winter in the mountains east of the Great 
Basin. 
Of the winter of 1849-50, he says: ‘‘I had hoped, from the representations which had been 
made to me of the mildness of the two previous winters, that we should be able to keep the field 
the greater part, if not the whole of the season; but, in the latter part of November, the winter 
set in with great and unusual severity, accompanied by deep snows, which rendered any 
further prosecution of the work impracticable.’’—(Page 120 of Report.) 
“«The winter season in the valley was long and severe. The vicinity of so many high mount- 
ains rendered the weather extremely variable; snows fell constantly upon them, and fre- 
quently to the depth of ten inches in the plains. In many of the cafions it accumulated to 
the depth of fifty feet, filling up the passes so rapidly that, in more than one instance, emi- 
grants who had been belated in starting from the States were overtaken by the storms in the 
mountain gorges, and forced to abandon everything, and escape on foot, leaving even their 
animals to perish in the snows. All communication with the world beyond was thus effect- 
ually cut off; and, as the winter advanced, the gorges became more and more impassable, 
owing to the drifting of the snow into them from the projecting peaks. 
‘We remained thus shut up until the 3d of April.’’-—(Page 122.) 
The Uinta terrace and the great plain of Green river no doubt possess the usual attributes 
of elevated table-lands, dryness of atmosphere, and great difference between the temperature 
of day and night, increased by their great elevation of 8,000 and 7,000 feet. But the precipi- 
tation on the mountains is very much greater. 
The winter temperature of the vicinity of the Great Salt lake is generally mild, tempered, 
no doubt, by the large body of salt water. That of the Great Basin generally, I should infer to 
be more severe. 
Dr. Wozencraft, of California, visited the plateau of the Sierra Nevada about the 10th 
January, 1854, and found the snow on the route of Lieutenant Beckwith to average six inches 
in depth, and nowhere reaching eight or ten inches in its average fall; but encountered one 
drift of snow on the eastern slope of the Sierra Nevada, in a ravine, extending a mile, averaging 
two feet or two feet and a half in depth. 
From the observations of the Surgeon General’s department, the results of which are tabulated 
below, it appears that of the 6.18 inches of rain that fell during December, 1853, January 
and February, 1854, at Fort Reading, on the Sacramento, in lat. 40° 28’, 1.18 inch had fallen 
previous to the 10th January, and this fell during December; that is, about one-fifth of the 
whole winter precipitation of that year had fallen previous to the 12th January. On that 
day, 1.30 inch of rain fell. 
The plateau of the Sierra Nevada partakes of the character of mountain and table-land. It 
is probable that on the western portion, at least as much rain falls as at Fort Reading ; on the 
eastern portion, probably much less. Should the winter precipitation be in the form of snow, 
it is probable, then, that 7.6 feet of snow falls on the western part of the plateau during 
December, January, and February—the mean winter fall of rain at Fort Reading being 7.6 
inches. The mean winter temperature of this portion of the plateau is not, probably, higher 
than 30°.2 Fahrenheit, that of Fort Reading being 47°.2 Fahrenheit. The temperature of the 
eastern portion is probably lower. 
