The Forest is unfortunately mis-named, for it is not a forest. There is not a single standing trunk, such as you may see occasionally in Utah or the Yellowstone. In the midst of a treeless plain the broken logs litter the ground in sections rarely over 25 feet long, oftenest in short chunks as if sawn apart, and in chips and splinters innumerable. Trunk diameters of 2 or 3 feet are common, and as high as 6 feet has been reported. It seems likely that the trees did not grow where they now lie but have been washed hither in some prehistoric swirl of waters, (as logs are carried down stream in our latter-day puny freshets,) becoming stranded in certain depressions of the land where we now find them, often having had their woody tissue gradually replaced by silica and agatized. Whence they came nobody knows, nor when. The guess of the unlettered guide who shows you about, may be as near right as the trained geologist’s, who locates the time of their fall as the Triassic Age, and their old home as perhaps beside some inland sea; but whether that was one million years ago or twenty, who can say, further than that they surely antedate the appearance of man upon this planet. The trees are evidently of different sorts, but mostly conifers apparently related to our present day araucarias, of which the Norfolk Island pine is a familiar example. Mr. F. H. Knowlton, botanist of the Smithsonian Institution, identifies then as _Araucarioxylon Arizonicum_, an extinct tree once existing also in the east-central United States.[63] Limbs and branches in anything approaching entirety are not found—only the trunks and infinite fragments are here. The coloration due to the presence of iron oxides in the soil at the time of silicification is often exquisite, in shades of pink, yellow, blue, brown, crimson—a never failing source of delight to visitors. Dr. L. F. Ward, of the United States Geological Survey, has said that “there is no other petrified forest in which the wood assumes so many varied and interesting forms and colors.... The state of mineralization in which much of this wood exists almost places it among the gems or precious stones. Not only are chalcedony, opals and agates found among them, but many approach the condition of jasper and onyx.”[64]