To provide against contingencies they strengthened the wickiup with another layer of poles, and Boyd spread over the leaves on the floor the skin of a huge grizzly bear that he killed on one of the slopes. They felt now that it was secure against any blizzard that might sweep through the mountains, and that within its shelter they could keep warm and dry in the very worst of times. But they did not sleep in it again for a full week, no rain falling at night during that period. Instead they spread their blankets under the trees. "It's odd, and I don't pretend to account for it," said Boyd, "but it's only progressive white men who understand the value of fresh air. As I told you, the Sioux never sleep outside, when they can help it. Neither do the other Indians. In the day they live outdoors, but at night they like to seal themselves up in a box, so to speak." "Rushing from extreme to extreme." "Maybe, but as for me, I want no better bed than the soft boughs of balsam, with blankets and the unlimited blue sky, provided, of course, that it isn't raining or hailing or sleeting or snowing. It's powerful healthy. Since we've come into Clarke Valley I can see, Will, that you've grown about two inches in height and that you're at least six inches bigger around the chest." "You're a pretty big exaggerator!" laughed Will, "but I certainly do feel bigger and stronger than I was when I arrived here. If the Sioux will only let us bide in peace awhile I think I may keep on growing. Tell me more about the Sioux, Jim. They're a tremendous league, and I suppose you know as much about 'em as any white man in this part of the world." "I've been in their country long enough to learn a lot, and there's a lot to learn. The Sioux are to the West what the Iroquois were to the East, that is, so far as their power is concerned, though their range of territory is far larger than that of the Iroquois ever was. They roam over an extent of mountain and plain, hundreds and hundreds of miles either way. I've heard that they can put thirty thousand warriors in the field, though I don't know whether it's true or not, but I do know that they are more numerous and warlike than any other Indian nation in the West, and that they have leaders who are really big men, men who think as well as fight. There's Mahpeyalute, whom you saw and whom we call Red Cloud, and Tatanka Yotanka, whom we call Sitting Bull, and Gray Wolf and War Eagle and lots of others.