LAGOONS AND SUBTERRANEAN DRAINAGE. 
137 
undulation. Six or seven miles away we can see tlie sylvan walls approach 
each other, leaving a narrow gateway between the tall spruces where the 
surface of the ground for a moment is sharply projected against the sky. 
The scene is, on the whole, a very attractive one. There is a great wealth 
of vegetation, somber indeed, and monotonous, but the darkness of the tone 
is suggestive of depth and richness of color. The only alleviating contrast 
is between the smooth expanse of the park and the myriads of sharp spikes 
which terminate the tree tops. The spirit of the scene is a calm, serene, 
and gentle one, touched with a tinge of solemnity and melancholy. 
About a mile from camp we came upon an object worthy of attention. 
It is a rather deep depression in the earth about 200 feet across and very 
nearly circular. Within it is a large pool of water. Its depth below the 
valley floor may be about 40 feet, and the depth of the water 5 or 6 feet 
in the middle. It is a fair specimen of a frequent occurrence upon the 
Kaibab. I have never seen them elsewhere, and the explanation is difficult. 
The interest lies in the mystery of their origin. In every day’s ride we 
usually find three or four of them and sometimes more. Some of them con- 
tain water, but the majority do not. Some hold water throughout the year, 
some only in the early summer or until autumn. They vary in size and 
depth very considerably. Some are as narrow as 20 feet; some are 300 to 
400 feet across. The depths vary from a yard or two to a hundred feet. 
The form is crater-like — always approximately circular. They do not 
appear to occur under any special set of conditions. They are found as 
often upon the platforms as in the valleys, and are not uncommon upon the 
slopes of the ravines. In a few instances traces may be seen of rain gullies 
or washes leading into them, but not often, and none have ever been noted 
leading out of them. Whatever running water may enter them sinks within 
their basins; but it is certain that many of them rarely receive any running- 
water. In the cases of those which do the wonder is that they do not soon 
fill up with sand and silt, for the water generated by heavy rain-storms or 
by melting snows, when sufficient in volume to run in a stream, is always 
tliick with mud. The scarcity of running water on the Kaibab has been 
mentioned. Yet the precipitation is comparatively great and the evapora- 
tion small. It is apparent that all the water which falls upon its vast 
