542 BIJIJ.RTIN 109, UNITED STATES NATIONAL MUSEUM. 



tion. The determining of the maximum and minimum amounts of 

 water in the streams; the periods of flood; the areas where the cli- 

 mate renders irrigation necessary and where unnecessary; the areas 

 in each valley of bottom and bench land adapted to irrigation, and 

 the relation existing in each valley between the area needing irriga- 

 tion; and the water supply and the times of different stages of 

 water — these are the chief factors in the problem. And it seemed 

 that there was no direction in which the survey could be of greater 

 service, both to the roads and the country, than in that of determining 

 the fundamental facts relating to the possibility of irrigation and ar- 

 tesian wells in this region. 



The intention was to make tJie record of the results of the sur- 

 vey essentially cartographic; to show upon the maps in a general 

 form all the physical facts that have an important bearing on the 

 prosperity of that region. 



Having this object in view from the beginning, the topographical 

 survey represented the form of the surface by contour lines of 200 

 feet vertical distance. The maps show the form of the surface, the 

 grades of the streams, the extent of the bottom and bench lands, 

 and the extent of the uplands. 



It was intended that one of these maps should show the mini- 

 mum known volume of water, at high and low water, in the princi- 

 pal streams, and the seasons at which these stages occur; and the 

 classified distribution of the soils and subsoils. This set was to ex- 

 hibit tl.e data needed to determine the practicability of irrigation 

 and under drainage. On anotlier set were to be shown the present 

 climatic conditions according to natural or local subclimate areas. 

 These were to show the i-ainf all and temperature by months, and the 

 phenomena which condition the success or failure of different crops 

 were to be mapped by areas and crop seasons. These maps were not 

 necessarily to be based, as regards these conditioning phenomena, 

 wholly on our short range of observations, for the reason that these 

 a re facts of general information, and traders, military officers, ranch 

 men, and Indians all observe and remember for years the times of 

 injurious frosts, of rlroughts, and the years of failure of the few 

 local crops. 



Another set of maps showed the distribution and relative abund- 

 ance of the various and numerous forage plants, and the climatic 

 facts conditioning success in stock grazing. 



A fourth set to show the mineral resources. On these were to be 

 represented the geological formations of the region, the outcrop- 

 pings of coal and the areas underlaid by it; and as the survey was 

 to test by drill and otherwise the character and thickness of the coal 



