russell.] ARTESIAN WELLS. 175 
depth of '240 feet delivers about 7 gallons of water per minute, having 
a temperature of 109° F. This well is within a few feet of a large 
hot spring having the same temperature, the flow of which was not 
diminished when the well was drilled. The elevation of the surface 
at this point, by aneroid, is 2,750 feet. The section passed through, 
as reported from memory by Mr. Roberson, is as follows: 
Section 2 miles north of Hot Spring post-office. 
Lig:ht-colored sandy clay (lake beds) 
Granular black layer, like basalt (volcanic lapilli?) 
Blue clay 
Black lava 
Total depth, about. 
Feet. 
Inches. 
236 
4" 
10 
■(a)" 
240 10 
a Several. 
The water is used for household purposes and for irrigation. 
Nearly opposite the well just described, on the east side of the 
valley and at an elevation approximately 50 feet higher, a well drilled 
to a depth of 230 feet, on land belonging to Mr. A. H. Pence, resulted 
in a small surface flow. 
On Mr. B. Whitson's ranch, situated on the eastern side of the val- 
ley, about 3 miles north of the two wells just mentioned, where the 
surface elevation is b}^ aneroid 2,750 feet, a well 700 feet deep dis- 
charges about one-third cubic foot of water per second. The temper- 
ature is reported to be 90° F. 
These three wells derive their water from different depths, and seem 
to indicate that water under pressure exists in at least three discon- 
nected pervious layers, or else that a source of supply more deeply 
seated than has been reached by any of the drill holes yet made charges 
porous beds above it through fissures. The abundance of hot springs 
in the same vicinity apparently favors the latter hypothesis. 
As will be shown below, the artesian wells in Bruneau Valle} T are 
within the border of a large structural basin, which it is convenient to 
designate the Lewis artesian basin. 
LITTLE VALLEY. 
Near the head of Little Valley, 9 miles west of Bruneau, there are five 
flowing wells, which range in depth from 150 to 215 feet, each drilled 
with a 2^ inch bit, and poorly cased. The water is of good quality; 
temperature is about 67° F. The flow varies somewhat with seasonal 
changes, being greatest in winter and spring and least in summer and 
fall. In most instances the pipes have become clogged and the dis- 
