4 BULLETIN 698, U. S. DEPARTMENT OF AGRICULTURE. 
ALTITUDE AND DRAINAGE. 
Most of this district is a high and nearly level table-land with 
an average altitude of about 4,000 feet and with a rather uniform 
slope to the east and southeast. The highest elevation reached is 
about 4,800 feet in the extreme northwest, while the southeasterng 
border has an altitude of only 1,500 to 2,000 feet. The eastern rim 
of the high plains is a rough, broken strip where the cap rock is being 
worn through and erosion is rather rapid. Still farther east, below 
the cap rock, the surface is rolling. 
Drainage is eastward through the tributaries of several rivers, 
among them being, from north to south, the Cimarron, Canadian, 
Red, Pease, Brazos, and Colorado. In the high plains, above the 
cap rock, these streams tend to form canyons, the most notable 
being that of the Red River from Canyon, in Randall County, east- 
ward for about 60 miles. 
SOIL. 
The soils vary in type from a light sand in some parts to a heavy 
clay or adobe in others, with clay soils predominating. The sandy 
soil is covered with bunch grasses, while the heavier soils are covered 
with a turf of buffalo, blue grama, and curly mesquite grasses. 
These soils are all quite fertile, to judge from their power to produce 
crops when there is sufficient moisture. They are, however, deficient 
in humus because of the scanty growth of the native vegetation. 
The absence of sufficient humus in the soil lessens its capacity to 
absorb and retain the moisture which falls upon it. It also leaves 
the soil in a condition to become puddled by heavy rains and to 
bake readily thereafter. 
CLIMATIC CONDITIONS. 
The United States Weather Bureau has maintained a weather 
station at Amarillo, Tex., in the heart of the Panhandle, since 1892. 
There are disconnected records from two Army posts covering an 
earlier period. The data herein considered are all from Amarillo or 
from the near-by cereal field station. 
The principal climatic features which influence crop production m 
the Panhandle are (1) a limited annual precipitation’ of irregular 
seasonal distribution, with a great loss of water due to run-off during 
torrential summer storms; (2) a relatively low atmospheric hu- 
midity; (3) a high average wind velocity; (4) a wide daily range of 
temperature, or hot summer days followed by cool nights; and (5) 
a very high rate of evaporation. 
PRECIPITATION. 
Moisture is the limiting factor in crop production in most of the 
Panhandle. Precipitation is the primary and most important 
factor in the moisture problem. 
