As one nears the geyser region, he gets the impression from the
columns of steam going up here and there in the distance--now from
behind a piece of woods, now from out a hidden valley--that he is
approaching a manufacturing centre, or a railroad terminus. And when
he begins to hear the hoarse snoring of "Roaring Mountain," the
illusion is still more complete. At Norris's there is a big vent where
the steam comes tearing out of a recent hole in the ground with
terrific force. Huge mounds of ice had formed from the congealed vapor
all around it, some of them very striking.