GEOLOGICAL SURVEY OF THE TERRITORIES. 219 



ingly important to know, not only that a mining section can produce 

 the principal cereals, as wheat, oats, and barley, and the more useful 

 vegetables sufficient to supply its own wants, but also to know something 

 in regard to the locality and extent of its arable lands. A few acres of 

 productive soil in the vicinity of a rich mine will often yield a greater 

 profit to the cultivator than a large farm in Ohio or Illinois. 



It is difficult to give any very reliable estimate of the land susceptible 

 of cultivation in the bounds of this district, as much of it is in small 

 bodies of irregular shape ; yet I think that by proper efforts at least 

 three thousand square miles, or about two million acres, can be brought 

 under cultivation. This may be thought an exaggerated estimate, when 

 we take into consideration the large proportion of the area occupied by 

 mountains, the barren tract south of the Sweetwater, and the deficiency 

 in the supply of water on the plains east of the Black Hills. But when 

 more effectual means of husbanding the water are adopted, as by tap- 

 ping the streams nearer their exit from the mountains, and keeping it 

 above the surface, by forming reservoirs, &c, the supply will be found 

 greater than at present supposed, and the estimate given, instead of be- 

 ing too large, will most likely prove to be too small. The cold climate, 

 it is true, is a serious obstacle, yet there are but few arable spots in the 

 district that cannot be made to produce useful crops of some kind. 



The district is naturally divided into four sections, as follows: The 

 North Park, the Laramie Plains, the Sweetwater region, and the plains 

 lying east of the Black Hills, forming, as it were, a winding series of 

 vast steps from the mountain height to the broad plains below. 



NORTH PARK. 



This elevated mountain basin, in which the North Platte takes its rise, 

 lies entirely within the bounds of Colorado Territory. It is about 

 fifty miles long from east to west, and thirty miles wide from north to 

 south, containing a surface area of some eight or nine hundred square 

 miles. The elevation varies from seven thousand five hundred feet to 

 nine thousand feet above the level of the sea, the average being about 

 eight thousand feet. 



The following description of this mountain cove, from a former report 

 made by Dr. Hayden, will convey a better idea of it in a few words than 

 auv description of my own. And, although several years have passed 

 since it was made, and glowing descriptions have since been published, 

 there seems to be nothing new added : 



The North Park is oval or nearly quadrangular in shape. Viewing it from one of the 

 high mountains on its border, it appears like a vast depression which might once have 

 formed the bed of a lake. Its surface is rather rugged, yet there are broad bottoms 

 along the streams, especially the North Platte and its branches. Scarcely a tree is to be 

 seen over the whole extent, while the mountains which wall it in on every side are dotted 

 with a dense growth of pine. The grass grows in the park quite abundantly, often 

 yielding at least two tons to the acre. Streams of the purest water flow through the 

 park, and there are some of the finest springs I have seen, a few of them forming good- 

 sized streams where they issue from the ground. I am quite confident that this entire 

 park would make an excellent grazing region for at least six or eight months of the 

 year. The soil is very rich, but the seasons must be too brief for the successful culti- 

 vation of any crops. Indeed, there is frost there nearly every night, and snow falls 

 every month in the year. On the north and east sides may be seen the snow-covered 

 ranges rising far above all the rest, their summits touching the clouds. On the west 

 side there is also a short snowy range. On the west side long ridges come into the 

 park and die out in the plain, forming a sort of en echelon arrangement. 



The soil is mixed with gravel and coarse sand on the ridges and upper 

 levels, but along the bottoms that flank the streams is rich and dark. 

 On the north £ide there is a quite sandy area. If future experiments 



