Some occur among the Cordilleras of the Andes, where cities, and towns, and cultivated farms are to be seen eight thousand feet above the level of the sea.
The Rocky Mountains, as we have already observed, occur sometimes singly or in groups, and occasionally in collateral ridges.

Between these are deep valleys, with small streams winding through them, which find their way into the lower plains, augmenting as they proceed, and ultimately discharging themselves into those vast rivers, which traverse the prairies like great arteries, and drain the continent.
While the granitic summits of the Rocky Mountains are bleak and bare, many of the inferior ridges are scantily clothed with scrubbed pines, oaks, cedar, and furze.

Various parts of the mountains also bear traces of volcanic action.

Some of the interior valleys are strewed with scoria and broken stones, evidently of volcanic origin; the surrounding rocks bear the like character, and vestiges of extinguished craters are to be seen on the elevated heights.
We have already noticed the superstitious feelings with which the Indians regard the Black Hills; but this immense range of mountains, which divides all that they know of the world, and gives birth to such mighty rivers, is still more an object of awe and veneration.

They call it "the crest of the world," and think that Wacondah, or the master of life, as they designate the Supreme Being, has his residence among these aerial heights.