IOC) CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
of these studies is now well advanced, however, and will appear 
shortly. In the present sketch, conclusions on several important 
economic problems must be reserved, awaiting results of special 
investigations now being conducted ; and those here given are tenta- 
tive and subject to revision in the complete report. 
A brief sketch of the geography, history, and production intro- 
duces general statements on such major features of areal geology as 
stratigraphy, intrusions, general structure of the Oquirrhs, and struc- 
ture of the district; and on such major features of economic geology 
as the character and occurrence of the ores, placer deposits, and com- 
mercial considerations. 
GEOGRAPHY. 
The Bingham district, which is the chief mining section in the 
West Mountain Mining District, lies in the north-central part of Utah] 
in latitude 112° 9' north, longitude 40° 32' west, and is situated on the 
east slope of the Oquirrh Range, 20 miles due southwest from Salt 
Lake City. It is connected with the main line of the Rio Grande 
Western Railway by a branch line which extends westward from 
Bingham Junction (11 miles due south of Salt Lake City) a distance 
of 14 miles to Ihe main settlement in Bingham Canyon. 
The Oquirrh Range, the most eastern of the desert ranges of the 
Great Basin, lies 25 miles west of the Wasatch Mountains, and 
extends in a general north-south direction southward from Great 
Salt Lake for a distance of 30 miles. In its general form it may be 
likened to that of a mason's trowel, with a handle-shaped portion at 
the north expanding at a point about 12 miles south of the lake from 
an average width of 6 or 7 miles to a width at the head of the blade 
of about 15 miles, and then gradually narrowing southward for a dis- 
tance of about 18 miles to a point. 
The main slorjes rise rapidly from elevations of about 5,000 feet 
on the surrounding desert — except at the junction with the Traverse) 
Mountains on the east and the Stockton bench on the west — to eleva 
tions on the main divide of over 9,000 feet at the northern and over 
10,000 feet at the southern portion of the range. These general slopes)^ 
to the east and west are deeply incised by many narrow, stecp-sidecH 
canyons, which extend from the deserts far in toward the main divide 
on comparatively gently rising, partially graded slopes, and then rise 
abruptly by exceedingly steep slopes. The slopes inclosing these i 
canyons are steepest at the lowest and highest portions, being often I 
precipitous immediately over the narrow, occasionally graded canyor 
bottoms, and similarly steep and ledgy along the major divides 
while a partially graded slope sometimes marks the intermedial 
stretches. These topographic characteristics are also true of th< 
branches and subbranches of the main canyon, with the qualitica 
tion that grading is much less advanced. 
Snow falls commonly in late October, accumulates to great depths 
