GEOLOGICAL SUEVEY OF THE TERRITORIES. 221 



presenting beautiful meadowy expanses, while other portions are rolling 

 and hilly and but sparsely covered with vegetation. The average eleva- 

 tion, as before stated, is about six thousand five hundred feet above the 

 level of the sea ; but, as will be seen below, different parts vary in height 

 as much as one thousand seven hundred feet, counting from the water 

 levels. As most of the streams in this section afford an ample supply of 

 water during the season when it is most needed for irrigation, their fall 

 becomes an important item in making up an estimate of the cultivable 

 lands. I therefore give the levels of the principal points of the three 

 larger. The North Platte at the railroad crossing has an elevation of six 

 thousand four hundred and seventy-seven feet, and at the mouth of the 

 Sweetwater nearly six thousand feet above the level of the sea, showing 

 a fall in this distance of about four hundred and eighty feet, or seven 

 feet to the mile. Medicine Bow Eiver at Medicine Bow Station has an 

 elevation of six thousand six hundred and ninety-eight feet, and at its 

 junction with the Platte about six thousand three hundred feet, a differ- 

 ence of nearly four hundred feet, or about eight feet to the mile. 

 Laramie River at Laramie City is seven thousand one hundred and 

 twenty-three feet above the level of the sea, and at tbe point where it 

 enters the Black Hills about five thousand four hundred feet, a difference 

 of over one thousand seven hundred feet, giving the very rapid fall of 

 eighteen or twenty feet to the mile.* 



These figures develop the important fact that not only the bottoms, 

 but also the upper levels, except where they are very high, can be irri- 

 gated. This must increase our estimate of the cultivable lands of the 

 section to an amount considerably beyond the area of the immediate 

 bottoms. 



The southeast part, to which the name " Laramie Plains " is some- 

 times limited, is decidedly the best portion of the section, and contains 

 much the largest proportion of arable land. Counting from the head 

 of the Laramie Valley to Rock Creek it is about seventy miles long, with 

 an average width of about twenty-five miles, giving an area of seven- 

 teen hundred and fifty square miles. Although the west end of this 

 area contains the dividing ridge between the Medicine Bow and the 

 Laramie, yet I think we may safely estimate that one-half of it can be 

 irrigated and brought under cultivation. The greater portion of this 

 beautiful valley is covered with a rich growth of grass, and presents the 

 appearance of one broad meadow, over which the numerous herds oi 

 cattle which are being gathered here to graze can be seen roaming. The 

 western part of this sub-section beyond Cooper's Lake presents a bar- 

 ren appearance until we reach the vicinity of Bock Creek. The creek, 

 although bordered by occasional bluffs, during most of its course is mar- 

 gined by fertile bottoms of moderate width, and tolerably well timbered 

 along its upper portion. Some of the southern tributaries of Medicine 

 Bow pass through fertile valleys, which can be easily irrigated and 

 brought under cultivation. The main stream passes for some distance 

 between rocky bluffs, with small bottoms on the alternate sides, but is 

 generally flanked by a moderately wide valley, with here and there 

 groves of cottonwood. I have not visited the valley of this stream or 

 that of the North Platte, north of the railroad, but from the informa- 

 tion obtained in regard to them, believe that by proper efforts they 

 would afford a considerable extent of tillable land. I have seen only a 



* The elevations along the railroad, are taken from the survey of that road. The 

 others are estimates made up from the harometric record kept by Mr. Beman during 

 the geological survey of the present season (1870,) and which he very kindly copied 

 and furnished me while in the field. 



