B. Silliman— Geological and Mineralogical Notes, etc. 195 
ArT. XXIV.— Geological and Mineralogical Notes on some of the 
Mining Districts of Utah Territory, and especially those of the 
Wahsatch and Oquirrh Ranges of Mountains ; by B. SILLIMAN. 
WITHIN the last two or three years, important developments 
have been made in the mineralogical and metallurgical re- 
sources of the eastern ranges of the North American Cordilleras 
of the Great Basin, and especially in the Wahsatch and Oquirrh 
Mountains of Utah, in the valley between which flows the Jor- 
an river, pouring the fresh waters of Utah Lake into the 
Great Salt Lake. It is in these two ranges of mountains that 
the most important and best known of the “ mining districts ” 
of Utah Territory are established. 
Commencing on the western slopes of the Wahsatch, near 
Salt Lake City, we find in order, going southward, the districts 
known as ‘‘ New Eldorado,” “ Big Cottonwood,” “ Little Cotton- 
wood,” and “ American Fork”; on the eastern flanks of the 
same range are the “Uintah” and “Snake Creek” districts ; 
while on the southern extension of the Wahsatch, are the 
The writer had occasion, in 1864, while studying the structure 
of the parallel ranges of Nevada, to note the fact, that these ranges 
were characterized by the existence in each of parallel zones of 
metallic veins; sometimes of the precious metals, almost without 
admixture of base metals, as in the Plutonic rocks of Western 
*Two hundred miles farther south, and chiefly in the counties of Beaver and 
ashingt Beaver River range” and “Mineral range, are 
Ohi. n, Star, Lincoln, Granite and Beaver districts in Beaver county, an’ 
Py and Warsaw districts in Piute county: some of these are probably silage 
hoe as yet only imperfectly explored districts, yielding copper, ‘ron, gold, 
silver, antimony, bismuth, &e. 
