undergrowth of shrubs, plants, and vines. It seems probable that the
forest once covered the western slopes of the mountains, but accident
and intention on the part of man has cleared broad sections. As soon
as the shade is removed, the land is invaded by a coarse grass (the
_cogon_), and this is burned over each year in order to provide feed
for the stock and to make good hunting grounds. The young trees are
killed off and reforesting prevented.

Numerous streams plunge from the high mountains toward the coast. In
places they rush through deep gorges between high mountains, again
they pass peacefully through mountain valleys. Everywhere they are
fed by minor streams and waterfalls until at last, as they emerge
into the broader valleys of the Abra and its tributaries, they are
rivers of respectable size.

The great central valley of Abra is far from being a level plain. In
places, as about Manabo, Bukay, and Bangued, there are stretches
of level land; but, for the most part, the country is rough and
broken. This valley is cut off from the sea by the Coast Range of
mountains which forms the provincial line between Abra and Ilocos
Sur, while another heavy spur forms the northern limits of Abra from
Ilocos Sur to the Cordillera Central. Two small and rather difficult
passes afford entrance from the coastal plain into the valley, but
the chief avenue of communication is the cut through which the Abra
river reaches the sea. So narrow is this entrance that, at high water,
the river completely covers the floor and often raises its waters
ten or fifteen feet up the canyon side. In recent years a road has
been cut in the rocks above the flood waters, but even to-day most
of the traffic between Abra and the coast is carried on by means of
rafts which are poled up the river. [7]