174 SNAKE RIVER PLAINS OF IDAHO. [bull. 199. 
the stratum of no seasonal variation. This high rate probably indi- 
cates that the lava sheets have not as yet completely cooled, but in 
part the abnormally high temperature may be due to fissure springs 
rising beneath the lava, and contributing to the water supply of canyon 
springs and of rock and artesian wells. 
ARTESIAN WELLS. 
A considerable number of artesian wells in northern Idaho are now 
flowing, but data concerning only a portion of them have as yet been 
procured. 
Included with an account of several artesian wells situated in the 
Boise quadrangle, and described by Lindgren in the Boise folio," are 
those which supply Boise. These are located near the immediate 
border of the Snake River lava and are highly suggestive as to the 
possibilities in other similar situations. 
There are two groups of wells near Boise— one in Hull Gulch, 1^ 
miles north, and the other about 2 miles east of the city. The first 
group consists of eight wells, six of which are reported to be 400 feet 
deep, and one 619 feet, but some changes were made during the 
summer of 1901, the results of which are not at hand; their combined 
flow is about 670 gallons per minute. The water is cold and of good 
quality. The second group consists of three wells, ranging in depth 
from 394 to 455 feet, which discharge about 550 gallons of water per 
minute, having a temperature of 170° F. This water is conducted to 
Boise in pipes and extensively used for heating purposes, baths, etc. 
Other hot wells are located in the same vicinity; they are described in 
the Boise folio. 
The unique water supply of Boise, consisting of both hot and cold 
water, furnished by flowing wells at small expense, makes it highly 
important to learn whether similar conditions exist near other towns. 
The only other town similarly situated in reference to geological condi- 
tions is Mountain Home, some statement concerning the water supply 
of which has already been made, and to which more attention will be 
given later. 
BRUNEAU VALLEY. 
In the upper portion of Bruneau Valley there are three flowing 
wells, each 2| inches in diameter, which, together with the numerous 
hot springs of the same region briefly described above, show that an 
abundance of water exists at a moderate depth under sufficient pres- 
sure to cause it to rise to the surface if openings are provided. 
On W. N. Roberson's ranch, about 2 miles north of Hot Spring 
post-office, and on the west side of the valley, a drilled well having a 
a Geologic Atlas U. S., folio 45. 
