

85 
The relation existing between the Colorado mountain system with 
its forests, aud the water supplies for agricultural purposes, is strongly 
stated by Prof. Cyrus ‘Thomas, of the Hayden Survey, as follows : 
This eastern mountain group appears to have two culminating points or radiating 
centers; the northern, and principal one, lies immediately around the North and 
Middle Parks, and forms the rim of these elevated basins; the other lies immediately 
southwest of South Park. In the first of these, Blue Bie , White River, Yampah 
River, and North Platte take their rise. In the other, Gana River, the Rio Grande, 
Arkansas, and main branch of the South Platte have their sources. The parks actas 
huge cisterns for the reception of the numerous little mountain rivulets that flow 
down from the surrounding rim, collecting them together and discharging them at 
one outlet. Thus, the North Park collects the various streams which form the North 
Platte; the Middle Park those that form Blue River; South Park those that form the 
South Platte ; the San Luis Park those that form the Rio Grande ; and the upper Ar- 
Kansas Valley, which is a true park, those which form the Arkansas River. Here, 
then, we see that five of the great rivers of this vast central region have their sources 
close together in this mountain area. Upon the peaks, ranges, parks, and forests 
embraced between the one hundred and fifth and one hundred and seventh meridians 
and the thirty-eighth and forty-first parallels, an area not exceeding 18,000 square 
miles, depend, in a great measure, the agricultural resources of an area of more than 
100,000 square miles. 
IRRIGATION SYSTEMS. 
It may be safely predicted that, within a comparatively few years, 
the Rocky Mountain region and adjacent portions of the Pacific slope 
will have irrigation systems equal to any the world has ever known. 
The discovery that vast areas of land, once deemed sterile and worth- 
less, are reclaimable by the application of water has given wonderful 
impetus to irrigation projects. Favorable legislation has been obtained, 
and various plans to effect the desired object have been well advanced. | 
By legislative act, in 1881, the State of Colorado created the office of 
State hydraulic engineer, and adopted a carefully devised code of irri- 
gation laws. Since then numerous irrigation enterprises have been 
begun and successfully prosecuted in that State. In many cases incor- 
porated companies have been formed for the construction of canals and 
reservoirs, and the distribution of water over wide tracts of land. In 
numberless other instinces, individuals, under the rule of priority of 
use, have made smaller canals and ditches, appropriating water in 
accordance with their needs and the existing rights of others. 
In the adjoining Territories, especially in Utah, systems more or less 
perfect have been introduced, and will be enlarged and improved as the 
necessities of the people may require. 
The data that have been collected with regard to the location and e eX- 
tent of the irrigating canals and ditches of this region, changes in the 
volume and flow of streams, etc., are given in the tables and maps ac- 
companying this report and in the descriptions of the several political 
divisions.* 

m Se e note on irrigation, page 61.) 
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