HAwortH. | Physiography of Western Kansas. pat! 
hundred yards to as much as half a mile. In such a ease the re- 
lation is so apparent that it can not be doubted. The character of 
the walls of these swales is similar to that of the arroyos already 
described. A pond no more than thirty feet in diameter, with a 
buffalo-grass sod covering the whole of its bottom, frequently has a 
vertical wall from 6 to 12 or 18 inches high. At other times the 
wall is more rounded, but such a vertical condition is sufficient to 
recall the similarity between their character and that of the arroyos. 
If the explanation of the origin of the vertical arroyo walls is cor- 
rect, this would be additional evidence in favor of the solvent ac- 
tion of the water in the swales being one of the causes in their pro- 
duction. The buffalo grass would be held in place on the surface 
of the bottom of the swale and of the arroyo, and as the material was 
dissolved from below the whole of the sod mantle would settle 
downward in a manner similar to the mantle of buffalo grass in the 
Arroyos. | 
The swales are most abundant on the high uplands where the 
Tertiary materials are the heaviest. Usually there seems to be no 
relation between their respective positions, but not always so. 
INDIVIDUAL STREAMS. 
We will now give a short discussion of the individual streams of 
western Kansas: | 
The Cimarron River. 
The Cimarron river rises near Raton, N. M., and flows eastward 
through southern Colorado and the southwest part of Kansas, ulti- 
mately emptying into the Arkansas river. In Kansas it has water 
in it throughout the greater part of the year in most of its course. 
It usually has a rise during the summer season at about the same 
time the Arkansas rises from melting snows. A considerable por- 
tion of the water in the river during the dry parts of the year is 
obtained from seeps and springs fed by the general underground 
water of the Tertiary areas. 
The valley of the Cimarron where it enters Kansas on the west 
is net very pretentious. The bluffs on either side of the stream 
are rounded rather than abrupt, and rise to a hight of from 100 
to 150 feet. The valley itself will average perhaps no more than a 
