24 
ECONOMIC GEOLOGY OF SILVERTON QUADRANGLE, [bull. 182. 
mines carrying abundant low-grade ore may be made profitable, even 
with the present low price of silver. Probably, as in the past, periods 
of depression will sometimes retard mining improvements. Yet it is 
clear that the resources of the district have been far too often super- 
ficially, ignorantly, or wastefully exploited. Although examples of 
extravagance are still not hard to find, there is now a more gen- 
eral realization of the distinction between such wasteful expenditure 
and the legitimate and often large outlay that makes possible the 
economical working of known low-grade ore bodies. It is very prob- 
able that the future will see a great and permanent increase in the 
productive development of such large and persistent ore bodies of low 
average grade. The decline in the price of silver, and also in that of 
lead and copper, which are important constituents of most of the ores, 
has greatly reduced the margin of profit and rendered economical 
working imperative, as is illustrated in the following table: 
Table showing the average annual prices of silver, lead, and copier, from 1880 to 
1899. 
Year. 
Silver. 
per fine 
ounce. 
Lead, Copper, 
per 100 per 
pounds, pound.a 
Year. 
Silver, 
per fine 
ounce. 
Lead, 
per 100 
pounds. 
Copper, 
per 
pound.a 
1880 
$1. 145 
1.138 
1.136 
1.110 
1.113 
1.065 
.995 
.978 
.940 
.936 
1 
$5.03 $0,216 
4.81 ; .188 
4.91 .185 
4.32 .159 
1890. 
1891 
$1,050 
.988 
.874 
.779 
.634 
. 658 
.674 
.603 
.588 
.601 
$4.35 
4.33 
4.07 
4.10 
3.28 
3.24 
2.97 
3.60 
3.75 
4.44 
$0. 156 
1881 
.128 
1882.. 
1892... 
1893.. 
1894 
1895 
.115 
1883 
.108 
1884 
1885 
3.74 
3.94 
4.61 
4.50 
4.41 
3.81 
.139 
.110 
.110 
.113 
.168 
.134 
.094 
.107 
1886 
1896 
| 1897. 
.109 
1887 
.112 
1888 
1898 
.119 
1889 
1899 
.177 
a Lake Superior ingot. 
The prices of silver are taken from the annual reports of the 
Director of the Mint. The lead and copper values are compiled from 
tables showing monthly prices and monthly range in the reports on 
mineral resources issued as parts of the annual reports of the Geolog- 
ical Survey. 
Although the first mine to be worked in the district was a gold pro- 
ducer, yet it is an interesting fact that foi § many years prospecting 
was practically restricted to a search for silver and lead ores. It was 
apparently owing to this adherence to an established routine that the 
Una and Gertrude claims in Imogene Basin, worked twenty years ago 
for silver and lead, were subsequently abandoned, with no knowledge 
of the remarkable gold ore which lay close alongside the argentiferous 
streak, and which was thrown out as waste. Masses of this rich ore 
were discovered by Thomas F. Walsh on the Camp Bird claim, and 
subsequently on the dump of the old workings of the Una and Ger- 
trude, and he purchased the latter in 1896 for $10,000. It is to-day 
