12 BULLETIN 588, U. S. DEPARTMENT OF AGRICULTURE. 
2to12 months. All of the wells but one were constructed before the 
range was reserved and are on private land. The pipe line was built 
in 1916 and carries the water from several mountain springs, a dis- 
tance of about 8 miles, to range difficult to provide with water by 
any other means. At the same time it relieves the range and water 
about the wells. One of the tanks was constructed in 1915 and five 
during 1916 for the double purpose of getting the cattle nearer water 
and relieving the range and water about the wells, os and 
permanent de 
Of the 15 tanks, one or more caught some of the run-off resulting 
from practically every shower that fell on the Reserve in 1916. In 
several instances this allowed the cattle to get onto fresh feed near 
water and make good gains in condition and at the same time cut 
down the expense of pumping and gave the hard-used range a rest. 
The cost of the five tanks constructed in 1916 was $787, which 
includes a reasonable compensation for the use of horses and mules 
employed in the work. The cost per tank varied from $53.40 to $309. 
The cost per cubic yard of earth in the embankment varied from 
$0.42 to $1.30, including time of travel between town and the tank 
site. A large part of the higher cost was for such travel. Even at 
this high cost the tank is considered a good investment, since it opens 
up range hitherto little used. The smallest of the five tanks should 
hold water at least two months after it is puddled and filled once; 
and the largest about eight months. 
The range of the Reserve is now one of the best watered units in 
southern New Mexico. On about 80 per cent of the area stock do 
not have to.travel more than 24 miles to water. This will aid mate- 
rially in carrying the stock through bad years with light losses and 
in good years will permit of increasing the number of stock. Although 
the pipe line and five new tanks were not available for use durig the 
dry season of 1916, the fact that the range was as well watered asit . 
was had its part in carrying the stock threugh with a loss of less than 
14 per cent for the year. 
Additional water will be developed, and careful bees will 
be made with the idea of determining more conclusively the point at 
which water development for a given type of range ceases to be a good 
business investment. 
CARRYING CAPACITY. 
To decide the number of stock that a range pasture or large range 
unit will carry year after year is one of the most difficult problems of 
range management. Private pastures, as well as range lands, are 
often overstocked and slowly depleted unintentionally through lack 
of knowledge of their carrying capacity and the effect of the over- 
stocking upon the forage production. The problem is complicated 
by the following facts: | 
