THE MISSOURI AND PLATTE RIVERS, ETC. 73 
very fertile, composed of the calcareous and aluminous marls of the 
Tertiary basin through which the upper portion of this river flows, and 
the clays of the Cretaceous system which forms the hills, and is the 
basis formation eee sea the valle 
The following day, May 11, we passed up the valley four or five 
miles above the “forks, for the pur pose of fording the river. The left 
fork is the main stream, and, at this time was much swollen and the 
current quite rapid, The bottom is so full of quicksands and. other 
impediments that we found it very difficult to discover a crossing place. 
Finally, after a most diligent search of — hours wading about in 
_ the stream, we ventured to make the attempt. We first unloaded 
everything i in our carts and carried it to the opposite side, a distance 
of one hundred and fifty yards, and then letting our carts down the 
steep bank with great care, we passed safely over on the other side 
with no other trouble than the miring of our horses in se or two 
| instances. After landing safely on the other side, we ascen e 
high hills which border the river, and camped in a "penetiinbon ravine, 
: which flowed a fine spring, surrounded with an abundance of 
wood, The whole country here has much the appearance of the lime- 
stone region near the mouth of the Platte, and I noticed several 
species of shrubs that are found no higher up on the Missouri than 
Council Bluffs. Our distance that day was not more than eight miles. 
The water of White river is very peculiar, oe a large quan- 
tity of sassy and aluminous matter held in suspension, so that it 
has much the appearance of milk. When “allOeed to stand for a 
short time, or ihibiiovér it is found in pools, a thick scum may bes 
— the surface very much of the appearance and —— of rich 
m,; removing aera and the thinner portion is ok lighte r 
bull boats for over one hundred miles from its mouth. We > fo und 
plenty of antelopes near our camping place. Our Indian killed two 
fine ones, which formed a most acceptable addition to our larder. 
n the following day we passed over a fine rolling upland prairie 
on the northern slope of the dividing ridge between White river and 
Running Water. After descending “two steep hills which border the 
river bottoms, pee — slopes gently towards the south for a dis- 
cance of fifteen o ——- nies _— a —_ ridge which is visible in the 
dist ance an 4 pene prmaie ith p nOur ur course W se nbout pe weet. 
2? 
* They posed Pai sppropratly na 
may things of the deepest interes this valley, nea as pao: it is 
a terra incognita. All Somat on the right side of — 
tiver flow from perpetual springs in the distant ridge, and even in 
