GEOLOGICAL SURVEY OF THE TERRITORIES. 227 



Horse Creek, 4,395 feet. From which it appears that the entire fall 

 from Eecl Buttes to Horse Creek is 1,133 feet, or an average of about 

 seven feet to the mile. The fall between the intermediate points are as 

 follows : From Red Buttes to the Bridge, eighteen feet to the mile ; 

 from the Bridge to Fort Fetterman, a little over seven feet to the mile; 

 from there to Horse Creek^ about the same. 



These figures develope a fact of the utmost importance in calculating 

 the agricultural capacity of this section. A fall of over one thousand 

 feet iu less than one hundred and fifty miles, with the volume of water 

 found in this part of the river, will give the means of irrigating an 

 immense amount of land. But in regard to this I will speak more fully 

 when I come to the more minute description of this part of the section. 



The elevation of Laramie bottom, at the mouth of Chugwater, is about 

 four thousand five hundred feet above the level of the sea.* The Chug- 

 water Valley, where the stage road to Fort Laramie strikes it, has an 

 elevation of five thousand four hundred and sixty feet ; Cheyenne, six 

 thousand and forty feet. 



Poison Spring Creek is a small stream coming down from the north- 

 west, and entering the North Platte at Eed Buttes. It runs through a 

 very pretty valley, averaging about one mile wide, flanked on the west 

 by a broad plain, which gradually ascends as it recedes from the stream. 

 On the east the hills rise rapidly to a sharp ridge running parallel with 

 the creek. It has been stated that the water of this stream is poisonous, 

 but I noticed some of our animals drinking from it as we crossed it, and 

 I think one of the men also filled a canteen with the water for drinking 

 on the road. No bad effects followed. Some two or three species of 

 plants were also growing luxuriantly in the stream. The amount of 

 water at the time we passed it (August) was small, but sufficient to irri- 

 gate the immediate bottoms. The entire valley was covered with a rank 

 growth of grass. 



Near the Red Buttes, in the bend of the North Platte, is a beautiful 

 bottom of perhaps one thousand two hundred or one thousand five hun- 

 dred acres of fertile soil. On one side of the river there is a thick grove 

 of cottonwood, willow, &c, but on the other (north) the timber has been 

 destroyed by emigrants and others who have camped at this point. 



Immediately below this the river enters a gorge or canon some eight 

 or ten-miles long, where, as a matter of course, no cultivable land worthy 

 of note is to be found. The slopes toward the river, except for a very 

 short distance, are not so precipitous as to present any serious obstacle 

 to the cutting of a canal around them, if it should be found necessary to 

 tap the river this high up. On the south side a canal could reach as far 

 up as the mouth of the canon above Red Buttes, but on the north side 

 the depression at Poison Spring Creek would present a serious obstacle 

 if commenced higher up than the upper end of the canon. As the fall 

 between Red Buttes and the Old Bridge is nearly or quite four hundred 



* The barometric readings taken by Mr. Beaman on the Laramie bottom, some two 

 or three miles above the mouth of the Chugwater, give four thousand five hundred and 

 thirteen feet as the elevation at that point. Four very uniform readings were obtained, 

 the weather being clear and cool. The distance from this point to Fort Laramie is 

 ■ about twenty-one or twenty-two miles. Mr. Fremont gives the elevation of Fort Lar- 

 amie as four thousand four hundred and seventy feet, while Stansbury, who, it seems, 

 camped on the same ground, or very near it, makes it four thousand five hundred and 

 nineteen feet. As we did not visit Fort Laramie, I have no means ot ascertaining where 

 the error lies. As Mr. Beaman's instrument did not admit of accurate readings nearer 

 than one tenth, an error of fifty or sixty feet might have occurred in his calculations. 

 As the Laramie runs pretty rapidly, the fall between Chugwater and the fort cannot 

 be less than one hundred feet. 



