98 
GEOLOGY. 
direction of the Colorado river and the head of the California gulf being unbroken by mountains, 
it at first seemed as if the water had formerly extended up as far as this water-line and that we 
were then, perhaps, below the level of the sea, or that the region had been upraised so as to effect 
its drainage. 
The valley or plain of the Desert was constantly expanding towards the southeast, the 
direction in which we continued to travel. The hounding ranges of mountains, limiting 
our view towards the north and northeast, gradually became more distant and less distinctly 
defined. A horizontal line, the heach-line of the former lake, was visible along their base. 
The surface of the desert appeared to descend by a gentle slope from the mountains on each 
side, the lowest ground thus being nearly midway between the ranges. 
We passed several Indian trails, and about noon met an Indian family travelling in the oppo¬ 
site direction. The young men came first, carrying hows and arrows and an old flint-lock 
musketoon; an old Indian and squaw followed, hearing the burdens. They stopped with sur¬ 
prise as we came up, and unrolling some rags from a great yellow hall invited us to eat. This 
proved to he made of the pounded beans and pods of the mezquite, which is an important article 
of food to them, hut prepared in that way, and partly fermented, was not a very agreeable 
refreshment to us. The adjoining valleys in the mountains and the upper portions of the slope 
of the Desert are inhabited by a tribe of Indians called Cohuillas. Up to the time of our arrival 
their country had never been visited by the whites with a train of wagons. As we approached 
some of their villages, we passed several holes dug in the clay, two or three feet deep, that con¬ 
tained water, and were evidently springs that the Indians had enlarged. The largest and best 
of these springs were surrounded by extensive rancherias, or villages of huts, located in thick 
groves of mezquit trees, which were quite abundant, and grew so thickly together that the 
Indian huts were completely hid. The Indians came out in great numbers to meet us, some of 
them well mounted on horses, but most of them on foot. The women and children were also 
attracted by curiosity, but were very shy ; many of them climbed to the tops of elevated plat¬ 
forms, where they appear to store their grain and melons, and thus obtained a good view of the 
long train as it passed to one of the springs where the grass was most abundant. We encamped 
at this place and were surrounded by crowds of Indians anxious to trade melons, squashes, corn, 
and barley, for pork, bacon, or other articles. 
The chief, or 11 capitan,” and the principal men having collected for a talk with Lieutenant 
Parke, they learned the object of our visit, and appeared much pleased. When questioned about 
the shore-line and water marks of the ancient lake, the chief gave an account of a tradition 
they have of a great water {agua grande) which covered the whole valley and was filled with 
fine fish. There was also plenty of geese and ducks. Their fathers lived in the mountains and 
used to come down to the lake to fish and hunt. The water gradually subsided “poco 
u poco,” (little by little,) and their villages were moved down from the mountains, into the 
valley it had left. They also said that the waters once returned very suddenly and overwhelmed 
many of their people and drove the rest back to the mountains. The vegetation around these 
springs was luxuriant, and wherever the clay was moistened, it supported either a growth of 
grass or of rank weeds. Saline incrustations were observed around the margin of the water, 
and on moist parts of the surface, some distance from it. Specimens were collected, (No. 261, 
of the catalogue,) and on examination are found to consist chiefly of common salt, with a por¬ 
tion of sulphate uf soda, sulphate of lime, sulphate of magnesia, and carbonate of lime. 
November 18.— Cohuilla Villages to Salt Creek —35 miles. —The Indians had a grand feast and 
dance during the night, keeping us awake by their strange songs and indescribable noises. At 
