J RUSSELL.] 
ROCK WELLS. 
173 
rises some distance up the drill holes. Reference is not here made to 
flowing wells, which will be considered later. 
Examples of wells which penetrate the stratified deposits beneath 
the Snake River Plains are furnished by those drilled by the Oregon 
Short Line Railroad between Pocatello and Caldwell. A list of 
these wells, with their depth, has been kindly furnished by W. H. 
Bancroft, vice-president and general manager of the Oregon Short 
Line Railroad. The height to which the water rises and the tempera- 
tures recorded are from observations made by Mr. Scott Turner. 
Well records along Oregon Short Line Railroad. 
Location of well. 
Total depth. 
Depth of 
water. 
Temperature. 
Wapi 
Feet. 
250 
425 
325 
401 
483 
450 
390 
600 
380 
114 
Feet 
Degrees /■'. 
Minidoka 
375 
265 
341 
430 
55 
Kimama 
56 
54 
Owinza 
Bliss 
70 
Cleft 
73 
Bisuka 
Owyhee 
530 
70 
Mora 
Nampa 
40 
61.5 
The success of these and other deep wells is good assurance that 
water can be had over large portions of the Snake River Plains if 
pumping can be resorted to. Near canyons the depth at which 
springs appear in their wells or bottoms indicates the depth at which 
rock wells would be successful, but the springs must, in most 
instances, be on the same side of a canyon as the site of the proposed 
well. If no springs occur in the canyon, wells located on the adjacent 
plains must be continued to a horizon below the canyon bottom 
before water can be expected to flow into them. Owing to irregular- 
ities in the thickness of the lava sheets, no accurate prediction can 
be made as to the depth to which a well should be carried at a distance 
from canyon springs, but in general can perhaps be assumed to be not 
less than 300 or 400 feet. It would not be surprising if in the broad 
plain tract, in the central part of which Big Butte is situated, rock wells 
would be successful at a depth less than that just stated, or from 150 
to 200 feet, but no tests have been made to show the truth of this 
assumption. 
An instructive result, based on the temperature of the water in the 
wells in the above list, is that the increase in temperature with depth 
is greater than the normal. As indicated by the data given (but 
not including the well at Nampa), the temperature gradient beneath 
the Snake River Plains is approximately 1° F. for each 45 feet below 
