The Delta of the Rio Colorado. 5 
useful in determining certain topographical features of the delta and 
its relation to the adjacent territory. Thus an old trapper who had 
frequented the river twenty-five years ago had left behind him the 
tradition that a channel left the main river above tidewater, and 
seventy-five miles from the mouth, and flowed southeasterly into the 
head of the Gulf of California—an assertion which had never been 
confirmed. The only known depression suitable for such a flood- 
waterway would be offered by the Santa Clara River,a shallow stream 
which heads back from the Gulf into the Sonora desert some distance 
from the river and sends a feeble current of salty water through its 
shallow reaches to the sea. An investigation of this feature from a 
FIG. 2.—THE SANTA CLARA RIVER, ONE OF THE HIGH-WATER OUTLETS OF THE 
COLORADO RIVER, NEAR COLONIA LERDO, 
camp near the head of the Santa Clara showed that the reddish waters 
of the Colorado left the main channel just above the “Colony Mesa” 
and flowed in great volume through a depression into the Santa Clara, 
forming a navigable stream which might easily, with a shift of the 
“a action of the current, become the main way of the Colorado. 
n immense amount of sediment, which has been estimated at 
binty million tons yearly, is carried down into the delta and deposited 
on the bars and banks of the various channels, giving rise to the 
assertion that appreciable construction of solid land has occurred 
within the observation of persons now living. This view is supported 
by the fact that the willows and poplars, which do not inhabit the 
lowest land moistened with brackish water, have advanced about ten 
