4 BULLETIN 1031, U. S. DEPARTMENT OF AGRICULTURE. 
Range Reserve * for a study of the problems involved. Investigations 
started soon afterwards are still in progress. Preliminary results 
were published in 1917.2, The object of this publication is to present 
results to date, with special reference to the period of drought in 
1916 to 1918, inclusive, and to outline the management and investi- 
gations proposed for the reserve in future based upon results and 
experience for 8 years, beginning in 1912. 
JORNADA RANGE RESERVE. 
The Jornada Range Reserve is an area of approximately 202,000 
acres of typical semidesert range lying in a basin adjacent to the 
Rio Grande Valley in Dona Ana County, N. Mex., about 50 miles 
north of the Mexican boundary. The major portion of the area 
is a flat’to slightly rolling plain varying in elevation from about 
4,100 to 4,700 feet, with a small mass of igneous mountains, the 
Dona Anas, at the southwest corner. The eastern portion of the re- 
serve, about one-fourth of the total, includes the western slope of the 
San Andres Mountains. 
The locality is one of the most arid in the Southwest. Records 
for 57 years, at State College, N. Mex., about 15 miles south of the 
reserve, show an average annual precipitation of 8.60 inches, with 
precipitation for individual years as high as 17 inches and as low 
as 8.50 inches. The main rainy season occurs in July, August, and 
September, with an average of 4.50 inches during these three months. 
* Temperature as high as 106° is common in summer, with almost con- 
tinuous high winds, low humidity, and consequently high evapora- 
tion. 
On the plains and foothills the soil 2 shows an almost entire absence 
of humus, and there is no change in texture with depth, except such 
as may be purely geological. The lime content is very high, and a 
highly limy layer or “ caliche” is characteristic. The development of 
this caliche layer 1s greatest under sandy or gravelly soils and least 
under the heavier clay soils. 
On the plains lght-textured soils, principally redish sand loams, 
loamy sand, and loose incoherent wind-blown soils predominate. 
On the rolling plain near the foothills of the mountains, areas of 
coarse gravelly soils are found, and in the center there are flats of 
1The Jornada Range Reserve was created by Executive Order May 3, 1912, at the 
request of the Department of Agriculture, with the idea of securing a complete range 
unit for conducting experiments and demonstrations in range management under con- 
ditions existing in southern New Mexico and similar country in adjoining States. The 
boundaries were slightly modified by Executive Order Apr. 24, 1916, and at present include 
about 202,000 acres. Since May 1, 1915, the investigations have been made by the 
Forest Service of the Department of Agriculture. 
2 Jardine, James T., and Hurtt, L. C., Increased Cattle Production on Southwestern 
Ranges, U. S. Dept. Agr. Bull. 588, 1917. 
-« Classification of soils on the reserve made by U. S. Bureau of Soils. 
