152 SNAKE RIVER PLAINS OF IDAHO. [bull. 199; 
water supply beneath the surface may for convenience be considered 
under two separate headings, namely, springs and wells. 
SPRINGS. 
The water reaching the surface from subterranean sources through 
natural conduits within the area embraced in the Snake River Plains 
forms canyon springs and fissure springs. Hillside springs are prac- 
tically absent, and cave springs are unknown. 
CANYON SPRINGS. 
Springs of this type occur on Snake River principally between Sho- 
shone Falls and the mouth of Bruneau River, where the stream has cut 
deeply into the lava sheets and associated sedimentary beds across 
which it flows. They are confined to the northern side of the river 
for the reason that the geological conditions on which their existence 
depends are not present on its southern side. Although much use is 
now being made of these springs for irrigation, far more water is sup- 
plied than is utilized, and the vast source of power they furnish is 
entirely unemployed. More than this, by excavating horizontal wells 
or tunnels the water may in numerous instances be made to flow at 
localities where it will be of greater service than at present. 
An attempt to indicate the value of the numerous springs that gush 
from the north side of Snake River Canyon in their order from Sho- 
shone Falls westward is here presented, but their full importance can 
only be determined by a detailed survey. 
At Blue Lakes the water issuing from large springs situated prin- 
cipally at the head of a side alcove opening from the main canyon is, 
as already explained, utilized for the irrigation of extensive orchards, 
which are highly productive. 
Below Blue Lakes to the point where the surprisingly great outflow of 
water occurs at The Thousand Springs, a distance of about 18 miles, there 
are a few small ranches, which are watered from springs. Although 
this portion of the canyon was seen by me only from above, I judge 
there are a number of localities where the water supply could be 
greatly increased or made to issue at a higher level, and thus be of 
greater service than at present. This means that not only the flat 
land due to deposits from the river can be irrigated, but also much of 
the rough talus slopes. The planting of trees and vines, not in straight 
rows, but here and there among the fallen blocks of rock, must be 
practiced in order that the great possibilities of the canyon may 
be fully developed. 
The most remarkable springs of Snake River Canyon begin about 
2 miles above where the Salmon River comes in, and extend west- 
ward to Bliss, a distance of about 18 miles. Throughout this por- 
