MINDANAO AND SULU : II. PHYSIOGRAPHY. 



353 



while certain of the most prominent points, such as Mount Gurayu, are 

 over 1,220 meters. It is for the most part treeless, and covered with a 

 rich, red soil. Cogon grass covers the greater part of the slopes. 



Physiographically, the Lanao upland is unique. It bears a very 

 striking likeness to the elevated prairies of the middle west of the 

 United States. A profile from Camp Overton to the lake and south 

 to Malabang is shown in figure 2. One very striking feature of this 

 region is Keithley escarpment, a bold ridge with an abrupt face to the 

 north and a long, gentle slope southward to the lake. A good idea 

 of the topography of this section is obtained from the panorama. (See 

 Plate IV.) It is the belief of many people who have seen this country 

 that Lake Lanao occupies a crater. The topography (see fig. 3) of 

 the country in general and particularly that of this escarpment does 

 not, to me at least, lend much encouragement to this supposition. It 

 is my belief that it is simply a basin between two well-defined mountain 

 ranges, which has been dammed by lava flows and an unusual accumul- 

 ation of wash from the hills. 



SKETCH OF COUNTRY 

 ABOUT CAMP KEITHLEY 



MI NDANA O P.I. 



Arranged By CapUamesM love Jrl5lnf 



and 



2? d LieutClarence A Mitchel I5lnf 



Jul y 26 19 06. 



SCALE 



IT-2 Mile. 



ICm.= l.28Km, 



Fig. 3. — Sketch of Topography near Lake Lanao, Showing the Keithley 



Escarpment. 



