246 GEOLOGICAL SUE\TEY OF THE TEEPvITOEIES. 



used in tlie buildings at the fort, as I am informed by Captain Wilson, 

 the polite of&cer in charge of the fort, was brought from Truckee, Cali- 

 fornia, and most of the other sawed lumber from Corinne. About fifteen 

 miles to the southeast some tolerably good pine and fir timber can be 

 obtained in the mountains. 



Leaving the fort we traveled northwest down the valley for a few 

 miles, to where it opens into the Snake Eiver 'Plain. This plain on the 

 east side of the river is here somewhat interrupted by sand dunes, 

 which have been piled up by the wind, reminding one very much of 

 those along the southern shore of Lake Michigan, a little east of Chi- 

 cago. Some of these were of considerable size, some entirely bare, but 

 as a general thing they were covered with a scanty growth of such 

 plants as covered the surrounding plain. 



Blackfoot Fork, which comes in here from the northeast, at the time 

 we crossed it contained a considerable volume of water, sufficient to 

 irrigate several thousand acres of the level plain through which it runs. 

 At this point it is some ten or twelve yards in width, and averaged 

 about three feet in depth, btit on my return, a month later, the volume 

 of water had decreased at least one-half. The hills to our right showed 

 very distinctly the direction and force of the wind, which at certain 

 seasons of the year must be quite severe. The mountains to the east 

 recede, and appear to be lower than those farther south. 



After crossing this stream we entered upon a broad, open plain, which 

 is an almost uninterrupted level, covered with grass and sage-bushes. 

 Eleven miles brought us to a small stream called Sandy Creek, which 

 runs in from the northeast. On each side of it, for a short distance, are 

 heavy accumulations of sand, which have been blown or washed into 

 rounded ridges and gradually flattened. Yet these sandy points are 

 mostly covered with ranker vegetation than the surrounding level. The 

 hills to our right, while receding from our course, decreased in height, 

 sending downward toward the west long, smooth slopes furrowed with 

 shallow ravines, often so regular and straight as to remind one of the 

 " lands " in the wheat-fields of Pennsylvania. But all around, as far as 

 the eye could reach, were treeless mountains, hills, and plain, bare, with- 

 out a grove beneath which a shelter might be found from the rays of 

 the sun, nothing to remind us of arborescent vegetation except the little 

 fringe of willows and cotton-woods that marked to our left the course 

 of Snake Eiver. 



From Sandy Creek to Taylor's Bridge, at the crossing of Snake Eiver, 

 the broad, level bottom is composed of a rich sandy loam that needs but 

 the addition of water to render it most excellent farming land. This 

 bottom, on the east side, is some six or eight miles wide, and stands at 

 a very moderate height above the ordinary water-level of the river. It 

 is flanked on the east by a terrace some fitteen or twenty feet above the 

 bottom. 



At the time we crossed the river, going north, it was quite full, and 

 rtished madly through and over the basaltic rocks that at this point line 

 its channel. The average width is about one hundred and forty yards, 

 and the average volume of water it sends down is probably 3 feet 

 deep by 400 feet wide, running at the rate of 4 feet per second, making 

 4,800 cubic feet per second. At the time we first crossed it, (June 24,) 

 the volume of water was more than double this, but on my return, nearly 

 a month later, it did not exceed the estimate I have given. This amount 

 of water will irrigate nearly- a thousand square miles of land sufficiently 

 for ordinary crops, such as the cereals. And as the general level is not 

 far above the average water-level, the canals need not be of very great 

 length, and therefore the water that returns to the channel can be used 



