326 



REPORT UNITED STATES GEOLOGICAL SURVEY, 



Iq general, the park is not well watered. Near its borders, especially 

 on the northern and western sides, there is at ail seasons an abaudance 

 of water, but throughout the whole interior part of the park water is 

 scarce away from the main streams. Its surface is covered with bunch- 

 grass of excellent quality, making it a first-class summer range for 

 sheep and cattle, but the great elevation makes it hazardous to attempt 

 to winter stock out of doors, except in sheltered nooks among the hills 

 at the southern end. The same cause makes it of little value as an 

 agricultural district, as only the hardiest crops can be matured. The 

 cultivable area is estimated at 174 square miles, distributed among the 

 South Platte and its branches, the Little Platte, High, Trout, and 

 Tarryall Greeks. 



In and about the course of the South Platte, from South Park to the 

 plains, there are several valleys of limited extent, but whose aggregate 

 area of tillable land is of considerable importance. On the river itself 

 there is a valley 6 or 8 miles long, between the foot of the upper caiion 

 and the mouth of Tarryall Creek, and another of about equal size a short 

 distance above the mouth of the North Fork. The latter stream and 

 Elk Creek each has a long narrow valley, containing a little arable land. 

 On the other side of the river, Beaver, Trout, and West Creeks each has 

 a small ^rea of arable land. The whole area of cultivable land on South 

 Platte drainage between South Park and the plains is 130 square miles. 



Profile of the South Platte River from its head to Julcslnirg. 



Head 



I'air Plav, South Park 



Mouth of Little Platte R\ver -_. - - - 



Poot of South Park (head of Upper Canon) 



Poot of Upper Caiion 



Mouth of Tarryall Creek 



Mouth of North Fork 



Exit from mountaina 



Denver 



Hughes 



PlatteviUe 



Evanfl 



Julesburg 



Miles. 

 314 

 300 

 275 

 264 

 254 

 244 

 22G 

 214 

 1(16 

 175 

 158 

 141 

 



S 



Feet. 



ii,noo 



9,800 

 8,683 

 8,165 

 7, gal 

 7,326 

 6, 110 

 5, 487 

 5, 150 

 5, 050 

 4, 950 

 4, 725 

 3,500 



Feet. 



85.7 



44.7 



47.1 



24.4 



59.5 



67.6 



51.9 



18.7 



4.8 



5.9 



13.2 



8.6 



Authority. 



Hayden. 



JJo. 



Do. 



Do. 



Do. 



Do. 

 Preliminary r/ulroad surveys. 



Do. 



Mean fall per mile in the plains, 9.4 feet. 



DRAINAGE AREA OF THE ARKANSAS RIVER. 



The drainage area of the Arkansas River in Colorado is 23,000 square 

 miles, of which by far the larger part is in the plains. The stream rises 

 in and near Tennessee Pass, flows at first about 25° east of south, through 

 a valley 18 miles long and of a width varying from 1 to 4 miles, ihen 

 follow a few miles of caOou, below which the valley expands again to 

 an average width of 4 miles, and continues thus to the mouth of the 

 South Arkansas, or about 33 miles. Here it enters a caiion, or narrow 

 valley, in which it is inclosed almost continuously to the plains. In one 

 place this valley widens out in a beautiful little park, known as. Pleas- 

 ant Valley, about 10 miles long by 3 in width. Tbe course of the river 

 changes half a dozen miles above the mouth of the South Arkansas to 



