tried to run, and not until they had again been brought down to a trot was he able to ask what it was, and to learn that it was a jack-rabbit.

By this time they had gone quite a long way, and as they reached the top of a ridge, Mr. Sturgis pointed toward a range of distant hills which cut off the view, and asked his nephew how far off he thought they were.

"Oh, I don't know, Uncle Will; how far are they?"

"They are about twenty miles distant, and we have to go ten miles beyond them. Do you see that low place in the line of the horizon, just to the right of the horses' heads? Well, we go through that. There is a narrow valley there, and we go up that, and then over the hill and down into the basin, where the ranch is."

"What makes those mountains look so grey, Uncle Will? They shine almost like silver. In some places the mountain looks black, but it's mostly grey."

"The black is the dark green of the growing pine timber, and the grey is where the timber has been burned, and is dead. For the first year or two after the fire has passed over the forest and killed them, the trees are black or keep their bark. Then the wind and rain and snow beating on the soft coating of charcoal, wear off the charred surface and the bark, and the wood becomes grey from the weather, just the colour of an old fence rail. The trees continue to stand for a good many years, and give this grey colour to the mountain side. Gradually the roots rot, and one by one the trees fall to the ground. Often they lie across each other, six or eight feet high, and this is the "down timber" which it is so hard to travel through. Sometimes it is even dangerous to pass through a piece of this dead timber. If it has been dead a long time, so that the roots of many of the trees have become rotten and weakened, the trees are easily thrown down by a high wind. I have seen a tall, thick tree pushed over by a mule knocking its pack against it, and in a gale of wind have seen the trees falling all around me. Of course, if one of them fell on a horse it would kill him."

By this time the waggon had begun to go down into some low but very rough and barren hills, cut up in every direction by ravines and water-courses. There was no grass and the ground was bare, except for low sage-brush here and there, and the rocks seemed to be bent and twisted. Sometimes a little pointed hill was capped by a great broad slab of stone, or again a narrow ridge was crowned with pinnacles which looked like pyramids or church steeples, or men or animals. It was a queer-looking place, and not like anything that Jack had ever seen before. He asked his uncle about it, and he explained. "These are what the old French trappers of early days used to call mauvaises terres—bad lands—because no grass grows on them. The soil is all sand or clay, and very dry. All this country you see was once the bottom of a big bay where the tide rose and fell."

"Tide rose and fell, Uncle Will! How could that be? Where did the tide come from? I didn't think that the ocean was within a thousand miles of here;" said Jack.

"That is true to-day, Jack," said his uncle; "but the time I am talking about was long, long ago, in what the men who study the earth's history call Jurassic time. No one knows how many years ago it was, but it is safe to say it was millions. In those times the salt ocean, or an arm of it, lay just east of the Rocky Mountains and the water in this bay where we are now was partly fresh and partly salt. Great forests grew here, and strange animals lived among them and fed along the shores of this bay. If we had time to get out and look for them, we could find beaches, where the sand was washed up by the waves, and shells, and the bones of these great animals. A big book could be written about these bad lands here, just as big books have been written about other bad lands."

"They're surely queer places," said Hugh. "I've seen it down in Kansas, and down on Henry's fork of Green River, and up in Oregon, where the ground was stuck full of bones and teeth. Some of the leg-bones was nigh as thick as my body, and some of the big heads had long teeth as long as my hand. They must have been big animals, and mighty dangerous too, I reckon."

"What makes the dirt all those different colours, Uncle Will," asked Jack; "In some places it's white, in others yellow or brown or black, and in some, bright red, like bricks."

"That red colour," said Mr. Sturgis, "is where the earth has been burnt. All through the soil here there are seams or veins of a crumbly brown substance, which is called lignite. It is a sort of coal about half made, and like coal it will burn. Sometimes a seam of this lignite catches fire from some cause or other, and may burn for years, baking the earth close to it. The heat turns it red, just as bricks which have been burned turn red."

By this time they were passing out of the bad lands and down into a flat through which flowed a broad river. There was no bridge over it, and Jack wondered how they were going to get across, but when they came to the water's edge the horses trotted in, were stopped to drink, and then walked on across, although the water came up to their bellies and washed and gurgled about the waggon, so that Jack began to think that perhaps they might be swept away. Pretty soon it grew more shallow, and then they came to the bank, and once more the waggon started off down the valley at a brisk rate. Soon they crossed a narrow little stream flowing between deep banks, climbed another hill, and then turning away from the river, went up a narrow valley, shut in on one side by a high wall of rock and on the other by a great mountain dotted with cedars. On this mountain Hugh said there were some mountain sheep, and he pointed out to Jack tracks in the road where some of these animals had crossed that morning. Further on, in a broad rolling valley, they saw some antelope, but by this time the cold wind had made Jack chilly and tired, and his uncle wrapped him up to the throat with blankets and robes, and propping him up between Hugh and himself, told him to go to sleep. Just as he was about to do this, something happened which woke him up very thoroughly.