moving rapidly about.
The mystery was soon explained. The Indian camp
was pitched on an open plain of several miles in extent,
which took a sudden bend half-a-mile distant, where a
spur of the mountains shut out the farther end of the
valley from view. From beyond this point the dull
rumbling sound proceeded. Suddenly there was a roar
as if a mighty cataract had been let loose upon the
scene. At the same moment a countless herd of wild
horses came thundering round the base of the mountain