The Grand Canyon of the Yellowstone has no equal on the face of the globe. With a breadth equal to its depth, this richly decorated canyon stands out unique among the world's wonders. Its beautiful panorama of stained walls, down which trickle streams of water which brighten the tints in some places and soften them in others, extends for a distance of three miles. The entire canyon is fifteen miles in length. A most interesting place to visit, but outside the itinerary of most tourists, is the Fossil, or Petrified, Forest. This section, especially attractive to the scientist, lies in the northeastern part of the park just north of Amethyst Mountain. To one who can read Nature's books, a wondrous volume is open, disclosing in its strata the hidden secrets of many by-gone geological ages. Here on the north flank of the mountain are two thousand feet of stratifications. On the ledges, tier above tier and story above story, are seen the opal and agate stumps and trunks of twenty ancient forests, some of the trunks being ten feet in diameter. What wonderful stories do they tell of life and death, of flood and volcanic fire, ranging through the eons of the past! So perfect are these petrifactions that the annual rings can be easily counted and even the grain of the wood is plainly visible. As one traverses this wonderland he is impressed by the evidence of the stupendous forces that lie smouldering beneath the crust of the earth. It is not improbable that at some future time, by the further wrinkling or sinking of the surface of this part of the American continent, the slumbering volcanic fires may be awakened to new life and activity. CHAPTER IV TWO PREHISTORIC CEMETERIES--GIANT REPTILES AND GIANT TREES Although reptiles appeared first in the period known as the Carboniferous Age, or age of plant life, they did not attain their greatest development until Jurassic and Cretaceous times, when many were of prodigious size and ruled the world. The gigantic ichthyosaurs, mesosaurs, and dinosaurs held dominion over the sea and land, and the monster flying reptile, the pterodactyl, over the air. Ages ago a great inland sea embracing Wyoming and the surrounding region occupied the area east of the Rocky Mountains. For many years students of geology had found this section a fertile field for the study of rock formations and the collection of fossils; but not until 1898 was the geological wonderland of central-south Wyoming discovered.