t group includes the fields of Canyon City (whose
product is the ideal domestic coal of the western states), Raton and the
South Platte; the Park group includes the Cones field and the Middle
Park; the west group includes the Yampa, La Plata and Grand River
fields--the last prospectively (not yet actually) the most valuable of
all as to area and quality. About three-fifths of all the coal produced
in the state comes from Las Animas and Huerfano counties. In 1901 about
a third and in 1907 nearly two-fifths of the state's output came from
Las Animas county. The Colorado fields are superior to those of all the
other Rocky Mountain states in area, and in quality of product. In 1907
Colorado ranked seventh among the coal-producing states of the Union,
yielding 10,790,236 short tons (2.2% of the total for the United
States). The total includes every variety from typical lignite to
typical anthracite. The aggregate area of beds is estimated by the
United States Geological Survey at 18,100 sq. m. (seventh in rank of the
states of the Union); and the accessible coal, on other authority, at
33,897,800,000 tons. The industry began in 1864, in which year 500 tons
were produced. The product first exceeded one million tons in 1882, two
in 1888, three in 1890, four in 1893, five in 1900. From 1897 to 1902
the yield almost doubled, averaging 5,267,783 tons (lignite,
semi-bituminous, bituminous, and a steady average production of 60,038
tons of anthracite). About one-fifth of the total product is made into
coke, the output of which increased from 245,746 tons in 1890 to
1,421,579 tons (including a slight amount from Utah) in 1907; in 1907
the coke manufactured in Colorado (and Utah) was valued at $4,747,436.
Colorado holds the same supremacy for coal and coke west of the
Mississippi that Pennsylvania holds for the country as a whole. The true
bituminous coal produced, which in 1897 was only equal to that of the
lignitic and semi-bituminous varieties (1.75 million tons), had come by
1902 to constitute three-fourths (5.46 million tons) of the entire coal
output. Much of the bituminous coal, especially that of the Canyon City
field, is so hard and clean as to be little less desirable than
anthracite; it is the favoured coal for domestic uses in all the
surrounding states.

Petroleum occurs in Fremont and Boulder counties. There have been very
few flowing wells. The product increased from 76,295 barrels in 1887 to
above 800,000 in the early