40 
passes that of the Atlantic states. In 
richness of variety and coloring, the 
flora of California is probably unsur- 
passed, and the arid regions of the 
state are not one whit behind the 
more attractive western. slopes. In 
springtime the stately lily of the des- 
ert (Hesperocallis undulata) wastes 
its sweetness on the desert air; every 
dry and thorny bush produces its 
quota of beauty, and a wealth of bril- 
liant annuals spring into brief exist- 
ance, 
During June and July, 1888, the wri- 
ter made his initial exploration in the 
Colorado desert, the main object be- 
ing the examination of various pros- 
pects of gold, silver, lead and copper, 
which had been discovered in the 
Chuckawalla mountains, for a gen 
tleman who was largely interested 
in their development. A brief report 
on this region, named the Pacific min- 
ing district, appeared in the tenth an- 
nual report of the California state 
mineralogist, 1890 (‘“‘The Colorado Des- 
ert,’’ by Charles Russell Orcutt, pages 
899-919). 
Lyell says:—‘‘Geology is the science 
which investigates the successive 
changes that have taken place in the 
organic and inorganic kingdoms of 
nature; it inquires into the causes of 
these changes, and the influence 
which they have exerted in modifying 
the surface and external structure of 
our planet.” 
In the decade commencing with 
1850 the more depressed part of the 
Colorado desert seems to have been 
known as the Cienega Grande, now 
hetter known perhaps as the Salton 
Sea,but more usually designated. as 
the Dry Lake; in 1870 we are told by 
early emigrants of that period that the 
Colorado river was in the habit of 
annually overfiowing its banks during 
the time of summer freshets, when the 
snows melted in the mountains whence 
the river has its source. This ‘‘annual 
overflow’ (as often omitted as other- 
wise, it is said) formed a channel 
through the deep alluvial bottom 
lands of the great basin, to which the 
name New River was applied by the 
earlier pioneers who crossed the des- 
ert on the oid overland route from 
41 
Ft. Yuma to San Diego. 
Along the course of New River, the 
Cocopa and other tribes -of Indians 
planted and raised magnificent crops 
on the overflowed lands. Corn, melons, 
squashes, and other vegetables, and 
grain, reached the rankest growth at- 
tainable, and some of these early pio- 
neers spoke with wonder of the fer- 
tility of the soil and the success 
attending. these Indians in their agri- 
cultural labors. These fertile lands 
were formed of the sediment deposi- 
ted by the waters of the Colorado 
river, and as the soil increased in depth. 
the overflow decreased; with the in- 
creasing infrequency of these overflows 
now of more rare occurrence, the In- 
dians were compelled to depart—the 
Cocopas retreating to the region of the 
gulf, the Cahuillas to the mountains 
around the northern arm of the desert. 
In 1890 the desert Indian huts might 
yet be found among the mesquite 
groves of New river, and in 1892 I found 
the Indians producing from the untill- © 
ed soil crops of promise, after.an over- 
flow of some of the lands below the 
United States boundary. 
“Approaching Carrizo creek, we saw 
for the first time in many days, strata 
of unchanged sedimentary rock. These 
consist of shales and clays of a light 
brown or pinkish color, forming hills of 
considerable magnitude at the base of 
the mountains. From their soft and 
yielding texture they have been eroded 
into a great variety of fantastic and 
imitative forms. This series of beds 
have been greatly disturbed, in many 
places exhibiting lines of fracture and 
displacement. Where they are cut 
through in the ped of Carrizo creek, 
they contain concretions and bands of 
dark brown ferruginous' limestone, 
Which include large numbers of fos- 
sils, ostreas and anomias. These have 
been described by Mr. Conrad, and are 
considered of Miocene age. In the de- 
bris of these shale beds I found frag- 
ments of the great oyster (Ostrea 
titan), characteristic of the Miocene 
beds of the California coast. A few 
miles north of this point, similar 
strata, probably of the same age, were 
noticed by Dr. Le Conte, but there they 
contain gnathodon, an estuary shell, 
