atal
activities eastward throughout the prairie states.

_Minerals._--Colorado is pre-eminently a mineral region, and to this fact
it owes its colonization. It possesses unlimited supplies, as yet not
greatly exploited, of fine building stones, some oil and asphalt, and
related bituminous products, a few precious and semi-precious stones
(especially tourmalines, beryls and aquamarines found near Canyon near
the Royal Gorge of the Arkansas river), rare opalized and jasperized wood
(in the eastern part of the El Paso county), considerable wealth of lead
and copper, enormous fields of bituminous coal, and enormous wealth of
the precious metals. In the exploitation of the last there have been
three periods: that before the discovery of the lead-carbonate silver
ores of Leadville in 1879, in which period gold-mining was predominant;
the succeeding years until 1894, in which silver-mining was predominant;
and the period since 1894, in which gold has attained an overwhelming
primacy. The two metals are found in more than 50 counties, San Miguel,
Gilpin, Boulder, Clear Creek, Lake, El Paso and Teller being the leading
producers. The Cripple Creek field in the last-named county is one of the
most wonderful mining districts, past or present, of America. Leadville,
in Lake county, is another. The district about Silverton (product
1870-1900 about $35,000,000, principally silver and lead, and mostly
after 1881) has also had a remarkable development; and Creede, in the
years of its brief prosperity, was a phenomenal silver-field. From 1858
up to and including 1904 the state produced, according to the State
Bureau of Mines (whose statistics have since about 1890 been brought into
practical agreement with those of the national government) a value of no
less than $889,203,323 in gold, silver, lead, copper and zinc at market
prices. (If the value of silver be taken at coinage value this total
becomes vastly greater.) The yield of gold was $353,913,695-$229,236,997
from 1895 to 1904; of silver, $386,455,463-$115,698,366 from 1889 to
1893; of lead, $120,742,674--its importance beginning in 1879; of copper,
$17,879,446-$8,441,783 from 1898 to 1904; and of zinc, $10,212,045--all
this from 1902 to 1904. Silver-mining ceased to be highly remunerative
beginning with the closing of the India mints and repeal of the Sherman
Law in 1893; since 1900 the yield has shown an extraordinary decrease--in
1905 it was $6,945,581, and in 1907 $7,411,652--and