85 



The relation o\isl iii<;' bet ween the Colorado mountain system with 

 its forests, and the water sup[)lies for agricultural purposes, is strongly 

 stated by Prof. Cyrus Thomas, of the Haydeu Survey, as follows : 



This eastern mouutaiu group appears to have two culmiuatiug points or radiating 

 centers; the northern, and principal one, lies immediately around tlie Nortli 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 River, White River, Yampah 

 River, and North Platte take their rise. In the other, Grand River, the Rio Grande, 

 Arkansas, and main branch of the South Platte have their sources. The parks act as 

 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. 



IREIGATION SYSTEMS. 



It may be safely predicted that, witliin a comparatively few years, 

 the Rocky Mountain region and adjacent portions of the Pacifie slope 

 will have irrigation systems equal to any the world lias 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 i^rojects. Favorable legislation lias 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 laud. In 

 numberless other inst.inces, 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 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.* 



* See note on irrigation, page 61. 



