180 
GEOLOGY: ATWOOD AND MATHER 
mineral deposits, and the largest settlements now are mining towns. 
They are Ouray, Telluride, Silver ton, Lake City, Creede, Rico, and 
Durango. About the margin of the range where agriculture has become 
of greater importance, and where fruit raising has been especially 
developed, are the towns of Montrose, Ridgway, Mancos, Ignacio, and 
Del Norte. 
As the lowlands bordering the range have been taken up for settle- 
ment, and the broader valley bottoms within the mountains have been 
fenced in for ranch lands, there has come a demand for a large amount 
of water for irrigation purposes. Glacial lakes, in many instances, 
have been modified so as to form great reservoirs, and certain of the 
canyons have been dammed so that the surplus waters from the melting 
snows and heavy rains may be stored and held until late in the growing 
season. 
The mountain slopes, where they are not too steep or too high, are 
clothed with magnificent forests. These are now under national control, 
and the ranchmen are assigned portions where they may graze their 
cattle, and in other portions, especially in the higher mountain areas 
and often in the glacial cirques or basins, thousands and thousands of 
sheep may be cared for during the summer. In return for this a fee 
is paid to the national government on a per capita basis. Where timber 
is cut either by the settlers or by lumbermen for commercial purposes, 
it is cut under the supervision of those in charge of the national forests. 
At the southwest base of the range is that region of remarkable human 
interest now set aside as the Mesa Verde National Park. It is one of 
the homes of the ancient cHff dwellers. The physiographic study of the 
Mesa Verde region indicates that the canyons in which those people 
built their homes were cut during and since the last glacial period. It is 
evident from the study of those homes that hundreds of not thousands 
of people once lived on this mesa. Today there is but a single spring, 
and that is near one of the smaller settlements. The articles foimd 
about these homes indicate that the people raised corn and cotton, and 
found in the chase an abundance of deer. Today the region is with- 
out game, and all the evidence available indicates that when the region 
was populated there was a much more moist climate. That does not 
prove that the cliff dwellers occupied those homes while there were 
glaciers in the mountains, but it is possible that our southwest country 
was inhabited by men at that time. The records from anthropology 
and geology are coming closer and closer together, and the further study 
of this portion of the continent from both points of view may lead to 
discoveries of imusual interest. 
