4 GEOLOGICAL SURVEY OF THE TERRITORIES. 



or valleys, its steeper or greater slopes, its peaks and passes, and this 

 with all the accuracy that it is possible to give on a map printed on a 

 scale of four miles to an inch, and in 200-foot contour-lines. These 

 topographical observations are directly founded on a careful secondary 

 triangulation, carried on simultaneously with them. At the principal 

 stations of this triangulation, stone monuments from four to six or more 

 feet in height were built, with a wooden stick, on which was deeply 

 carved the number of the station and of the map (according to the 

 scheme of maps of the survey), inserted in each, thus rendering 

 them available in the future, when more accurately located by the pri- 

 mary triangulation, as data on which to base the usual United States 

 land surveys when these may be needed in these distant regions, or for 

 other purposes of references. 



Further, the general quality and distribution of timber, bottom, agri- 

 cultural, arid, or generally unavailable lands, were also made the sub- 

 ject of observation ; while botanical, natural-history, and other speci- 

 mens were collected as far as possible; and the amount of water flowing 

 in the larger streams was made, in some cases, the subject of measure- 

 ment. A permanent and quite complete meteorological station was 

 established at the White Eiver agency, the base of supplies of the party, 

 while similar observations were at one time continuously taken for 

 nearly three weeks at a point near the head of the White Eiver, and 

 again for nearly four weeks at the junction of the Eagle and Grand. In 

 comparing with these bases the observations constantly made with the 

 party, very complete and accurate hypsometric results will be obtained. 

 In these observations, the usual mercurial mountain-barometer of James 

 Green, with wet, dry, maxima, and minima thermometers, was employed. 



As the general results, regarding the occurrence of economic products, 

 it may be said that the series of older metamorphic rocks, such as the 

 . granites, schists, etc., of probable Archean age, in which alone the 

 precious metals and minerals of Colorado have been found, and which, 

 form the foundations on which all the bedded rocks, sandstones, lime, 

 stones, etc., of the country rest, are brought to the surface and exposed 

 only along the folded ridges of the Park range, and in the bottoms of a 

 few canons in some of the southern tributaries of White Eiver, and of 

 the neighboring tributaries of the Grand, and that it is only in these 

 regions, therefore, that the precious minerals may be looked for. Along 

 the northern portion of the district, north of the main valley of "the 

 White, and in the extreme west, the surface of the country is formed of 

 rocks of Cretaceous age, which are, for the most part, horizontal beds, 

 flexed here and there into quiet undulations. The coal of the region, 

 which consists of a few seams of fair Lignitic coal, seems to be confined 

 wholly to pretty definite horizons in the upper-middle and upper por- 

 tions of this group ; and as these particular horizons have been eroded 

 away from the region in question, except at the north and west, it is here 

 alone that it becomes worth while to search for coal. Farther west, it is 



