In the old depressions where the ice had chiselled away the softer rocks, there were formed lakes of the standing water, and one of these was more than thirty miles long, winding in and out among the mountain-ridges.  In the lake bottom the water soaked through down to the hot lava below, from which it was thrown boiling back to the surface again, fountains of scalding water in the icy lake.

The cold Ice age has killed all the plants in the region; and it had driven off the animals that could be driven, and had then buried the rest.  But when the snow was gone the creatures all came back again.  Grass and meadow-flowers of a hundred kinds came up from the valleys below.  The willow and the aspen took their place again by the brook-side, and the red fir and the mountain pine covered the hills with their sombre green.  The birds came back.  The wild goose swam and screamed, and the winter wren caroled his bright song—­loudest when there seemed least cause for rejoicing.  The beaver cut his timber and patiently worked at his dams.  The thriftless porcupine destroyed a tree for every morning meal.  The gray jay, the “camp robber,” followed the Indians about in hope that some forgotten piece of meat or of boiled root might fall to his share; while the buffalo, the bear, and the elk each carried on his affairs in his own way, as did a host of lesser animals, all of whom rejoiced when this snow-bound region was at last opened for settlement.  Time went on.  The water and the fire were every day in mortal struggle, and always when the water was thrown back repulsed, it renewed the contest as vigorously as before.  The fire retreated, leaving great stretches of land to its enemy, that it might concentrate its strength where its strength was greatest.  And the water steadily gained, for the great ocean ever lay behind it.  So for century after century they wrestled with each other, the water, the fire, the snow, the animals and the plants.  But the fishes who had once lived in the mountain torrents were no longer there.  They had been boiled and frozen, and in one way or another destroyed or driven away.  Now they could not get back.  Every stream had its canon, and in each canon was a waterfall so high that no trout could leap up.  Although they used to try it every day, not one ever succeeded.

[Illustration:  “AND IN EACH CANON WAS A WATERFALL.”]

So it went on.  A great many things happened in other parts of the world.  America had been discovered and the colonies were feeling their way toward the Pacific Ocean.  And in the vanguard was the famous expedition of Lewis and Clarke, which went overland to the mouth of the river Columbia.  John Colter was a hunter in this expedition, and by some chance he went across the mountains on the old trail of the Nez Perces Indians which leads across the Divide from the Missouri waters to those of the Columbia.  When he came back from the Nez Perces trail he told most wonderful tales of what he had seen at the head