easily from one peak or ascent to another over a natural connecting
embankment. On either side of this connecting ridge is the head of a
deep, steep-walled canyon; the ridge is only a few hundred feet broad
at base, and only half a dozen to twenty feet wide at the top. These
ridges invariably have the appearance of being composed of soft earth,
and not of rock. They are appreciated by the primitive man, who takes
advantage of them as of bridges.

The mountains are well watered; the summits of most of the mountains
have perpetual springs of pure, cool waters. On the very tops of some
there are occasional perpetual water holes ranging from 10 to 100 feet
across. These holes have neither surface outlet nor inlet; there are
two such within two hours of Bontoc pueblo. They are the favorite
wallowing places of the carabao, the so-called "water buffalo,"[6]
both the wild and the half-domesticated animals.

The mountain streams are generally in deep gorges winding in and out
between the sharp folds of the mountains. Their beds are strewn with
bowlders, often of immense size, which have withstood the wearing of
waters and storms. During the rainy season the streams racing between
the bases of two mountain ridges are maddened torrents. Some streams,
born and fed on the very peaks, tumble 100, 500, even 1,500 feet
over precipices, landing white as snow in the merciless torrent at
the mountain base. During the dry season the rivers are fordable at
frequent intervals, but during the rainy season, beginning in the
Cordillera Central in June and lasting well through October, even
the natives hesitate often for a week at a time to cross them.

The absence of lakes is noteworthy in the mountain country of
northern Luzon -- in fact, in all of northern Luzon. The two large