268 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
small amount finds a market in the northern peninsula of Michigan 
and in Wisconsin. The coal of this field is inferior to that of Penn- 
sylvania and Ohio, and can compete with the latter only when it has 
a decided advantage in the matter of freights. 
The markets of the Eastern Interior field are also chiefly within its 
own limits and in immediately adjacent regions. It supplies the 
Chicago market in part and also some territory to the northwest and 
southwest. It occupies a central position among the Carboniferous 
coal fields, and its product comes in competition with that from all 
the others. It supplies the markets westward to the margin of the 
Western Interior field, but goes eastward only a short distance into 
the region which separates it from the Appalachian field, where it 
competes not only with the better coal from the latter field, but also 
with the cheap fuel supplied by the natural gas fields of Ohio, Indiana, 
and Kentucky. 
The Western Interior field supplies the markets within its own 
borders and toward the north and west, where it comes in competi- 
tion with the Rocky Mountain fields. 
The Southwestern field supplies the markets in a large territory 
toward the south and west, in which it had little competition until the 
development of the California and Texas oil fields made liquid fuel 
available. Practically all the coal used by the Southern transconti- 
nental railroads, as well as the Texas roads, comes from the north 
Texas and Indian Territory fields. The hard coals of the Arkansas 
field supply an extensive region west of the Mississippi River with 
a high-grade domestic fuel, which bears a relation to the neighbor- 
ing soft coals somewhat similar to that borne by the Pennsylvania 
anthracite to the Appalachian bituminous coals. 
Considering the entire region between the Appalachian coal field 
and the Rocky Mountain fields, there is observed a general westward 
movement of the coal. Thus the product of the Western Interior 
field goes west almost exclusively, that of the Eastern Interior field 
goes west to and within the borders of the Western Interior field, 
while the Appalachian coal goes west across both the Eastern and 
Western Interior fields and beyond the territory of the latter, com- 
peting with the Rocky Mountain coals to some extent. This west- 
ward tendency is due chiefly to the higher grade of the Eastern coals, 
but in part also to the fact that railroad freight rates are generally 
lower westward than eastward; water transportation also favors the 
westward rather than the eastward movement of coal. 
The region west of the one hundredth meridian, which constitutes 
about half the area of the United States exclusive of Alaska and the 
other outlying possessions, contains less than 20 per cent of the coal 
fields. The largest area entirely without coal lies between the Rocky 
Mountains and the Pacific coast. This, however, is a region in which 
