There are no islands, and the river, narrowed to about half a mile, flows with a rapid current.

In some places it runs five miles an hour, and its depth is from fifty to a hundred feet.

The mountains come to the river on either bank, sometimes in precipitous cliffs, but generally in regular slopes.
Their elevation is about a thousand feet, and they are covered to their summits with dense forests of foliferous and coniferous trees.
Occasionally the slopes are rocky or covered with loose debris that does not give clinging room to the trees.

The undergrowth is dense, and everything indicates a good vegetation.
The mountains are of mica-schist, clay-slate, and rocks of similar origin resting upon an axis of granite.

Porphyry has been found in one locality.