m4 BULLETIN 367, U. S. DEPARTMENT OF AGRICULTURE. 
to as nearly the same treatment as the adjacent unfenced range 
recelved as was possible under the circumstances. When these ex- 
periments were begun in 1903 the problems which presented them- 
selves for solution were as follows:1 
(AD)e2Ro demonstrate that under proper treatment run-down and overstocked 
ranges will recover, a statement of fact that was very much doubted by stock- 
men when the experiments were begun. 
(2) To ascertain how long a time is necessary to get appreciable and com- 
plete recovery, and what methods of management will produce such results. 
(8) To carry on reseeding and introduction experiments in the hope of 
increasing the total quantity of feed. 
(4) To measure as accurately as possible the carrying capacity of a known 
representative area. ; 
Results have already been published? relating to the first three of 
these questions. The present bulletin presents the data on carrying 
capacity which have been obtained so far. The methods of making 
collections originally established * have been continued. Hay-cutting 
operations have been carried on for five years, and records of the 
number of “animal-days’” feed* used on measured areas of the 
reserve have been obtained by recording the number of stock on 
given areas for a period of seven years. From the hay-cutting rec- 
ords and the estimates based upon the collections an estimate of the 
carrying capacity is made, and this is compared with the actual 
results obtained from the pasturing records. Some additional mis- 
cellaneous observations relating to the project are included. 
The generalizations presented here apply strictly to the area in- 
dicated on the map. They could be apphed without modification to 
exactly similar localities and conditions. They doubtless present a 
statement of conditions closely similar to those on many other parts 
of the southwestern arid grazing land; they will be usable with but 
shght modification over most of southern Arizona, and to some ex- 
tent in New Mexico and western Texas. 
Three maps of the area studied are given for the better under- 
standing of the region. One of these (fig. 1) presents the main re- 
lef features of the reserve, being based upon the Patagonia quad- 
rangle of the United States Geological Survey contour map of the 
Santa Rita Mountain region. Another is an outline map (fig. 2) 
that shows where collections of material were made. The small 
letters (without accent) refer to the spring collections made in the 
years 1903 to 1908, inclusive. The accented small letters refer to the 
1See Bureau of Plant Industry Bulletin 67, preface. 
2 See Bureau of Plant Industry Bulletins 67, 117, and 177. 
*See Bureau of Plant Industry Bulletin 67, p. 24 et seq. 
4 As used in this bulletin, an ‘‘ animal-day’s”’ feed equals the feed necessary for one 
mature animal, cow, steer, bull, horse, or burro, for one day. Calves or colts when Six 
months old are counted as mature animals, but are not counted at all before that time, 
