GEOLOGICAL SURVEY OF THE TERRITORIES. 235 



its entire length through a level sage plain, averaging about twenty-five 

 or thirty feet higher than the surface of the creek. The immediate bot- 

 toms are generally narrow, and often wanting on one side. The fall 

 of the creek here is sufficient to carry the water on the plains, but the 

 supply is not sufficient to irrigate a belt more than a mile or two in 

 width. The country bordering the upper portion of Little Sandy is 

 somewhat broken and hilly, particularly on the east side, but it enters 

 the plains before it is joined by Pacific Creek, and is flanked through- 

 out by all the level land its waters can irrigate. 



The Big Sandy, from the point where it is joined by the little Sandy 

 to its mouth, runs through a narrow valley, generally flanked on one 

 side by tolerably high bluffs, which are the margins of the elevated 

 plains that here rise from seventy -five to one hundred feet above the 

 creek. The average width of the immediate bottoms is, perhaps, half a 

 mile, but the upper level can be reached with canals a few miles long, 

 and the breadth of cultivable land increased to the full extent of the 

 supply of water. The elevation of the little Sandy bottom, just above 

 its junction with Pacific Creek, is six thousand four hundred and fifty 

 feet above the sea, while that of Big Sandy bottom near Big Timbers — 

 twenty-five miles by the road from the former — is five thousand eight 

 hundred and eighteen feet. This shows that between these points 

 there is a fall of over twenty feet to the mile. Ten miles further down, 

 where it empties into Green Eiver, the altitude is five thousand five 

 hundred and six feet above the sea level, showing a fall of nearly thirty 

 feet to the mile, which is sufficient to reach the highest plateaus which 

 border the valley. 



Although I traveled over this sub section, and noted carefully every- 

 thing observable bearing upon its agricultural capacity, yet I am unable 

 to form any very reliable estimate of the area of its irrigable lands. This 

 difficulty arises from a want of information concerning the volume of 

 water these streams send down during the irrigating season. If, as is 

 probably the case, they are much larger at that season than when we 

 crossed* them, then the estimate of the tillable lands must be much 

 larger than if judged by the water at the time of our visit. Assuming 

 the larger volume, I would place the estimate at about one hundred and 

 twenty square miles in this sub-section. 



The average elevation of this entire section is between five thousand 

 five hundred and six thousand five hundred feet above the sea level, 

 which is lower than that of the Laramie Plains, but the climate is not 

 so temperate as that of the Salt Lake basin. Wheat, oats, barley, and 

 such roots and vegetables as are mentioned as growing at Laramie City, 

 can be raised here. 



The north part of the Green Eiver Valley may have some good graz- 

 ing fields, but neither the lower part of this valley nor that of the 

 Sandy afford any very extensive or valuable areas suitable for pasturage. 



There is some cotton wood along the Green River and the lower part 

 of Big Sandy, but as a general thing this entire region is destitute of 

 timber, none being found nearer than the mountains. 



The remainder of my report on this district relates only to such 

 detached portions as were visited by the expedition. 



Black's Fork, to the point where it is joined by Ham's Fork, is bor- 

 dered by a bottom of moderate width, which will afford space for a 

 number of farms, and a grazing area of considerable extent. At the 

 time of our visit to this place, a drove of one thousand cattle was rest- 

 ing and feeding here, preparatory to their departure west. This stream, 

 to its junction with Green Eiver, is flanked by narrow bottoms, which 



