RANGE WATERING PLACES IN THE SOUTHWEST 13 
locations, as well as places, where it 1s improbable that adequate 
water will be found at a reasonable depth. Information as to the 
probabilities of ground water can frequently be obtained from par- 
ties having familiarity with local conditions, such as the State en- 
gineer, chief engineer of the State board of health, or professors of 
engineer ing in State universities or agricultural colleges. 
Since the seventeenth centur y numerous publications have treated 
of “water witching,” the use of forked sticks, or so-called divining 
rods, as means of locating underground water. The United States 
Department of Agriculture and the United States Geological Survey 
discourage the expenditure of time and money for such services 
(26) (7). 
DUG WELLS 
Where adequate water-bearing strata occur within from 50 to 60 
feet of the surface dug or blasted wells are often satisfactory. They 
are usually not so dependable as deeper wells during the dry seasons, 
however. Dug wells have the advantage of large underground 
storage capacity, which is important where the flow is weak. In 
occasional instances adequate. storage has been obtained by sinking 
a second well beside the first. If they penetrate unconsolidated de- 
posits of earth and rock, they should be walled with rock, concrete, 
or timber to prevent caving. All wells should be covered to prevent 
pollution of the water and accidents. 
Where the water supply is weak and apparently comes from 
numerous tiny seepages rather than from heavy flows, the yield of 
wells has occasionally been increased by the lateral extension of 
one or more galleries, or horizontal tunnels, from near the base of 
the shaft. This method has proved especially effective where such 
tunnels were extended beneath a porous stream bed. 
DRILLED WELLS 
If it is necessary to go deep in order to find a dependable water 
supply, drilled wells offer the most feasible method of obtaining: it. 
Their limited storage capacity, however, makes it necessary to “tap 
strata carrying rather abundant supplies of water. Wells with a 
yield of only a few gallons per minute, which would be failures for 
irrigation purposes, may be adequate for w atering livestock if the 
supply is stored. Most of these wells take casings from 4 to 6 
inches in diameter and are less than 300 feet in depth. Over much 
of the Southwest the advisable depth limit is between 500 and 700 
feet, depending upon the needs. Occasional successful wells exceed 
1,000 feet. 
The cost of an extremely deep well, fully equipped with storage 
tank, windmill, and engine, may be $10,000 or more. Operation and 
maintenance are also heavy items of expense, which definitely limit 
its use. Such an outlay is seldom warranted, though a large range 
that does not have an otherwise dependable water supply will 
justify a large investment in obtaining one or more deep wells to 
provide water at key locations on the range as insurance against a 
water famine. This is especially true on sheep ranges, where water- 
ing places are not required at close intervals. 
