Under primitive conditions, buffalo herds numbering millions of animals regularly migrated in spring and fall from one feeding ground to another, often traveling hundreds of miles for this purpose. The herds followed the same routes year after year and made lasting trails, often from two to three feet in depth. Investigation has shown that many of our highways, and even some of our main railway lines, seeking the most convenient grades, follow trails laid down by these early pathfinders. When a great migrating herd was stampeded, the thunder of its countless hoofs shook the earth, and in its flight it rushed like a huge black torrent over the landscape. The buffalo was the most important game animal to the Indians over a great area. Several tribes were mainly dependent upon these animals for food and clothing and the entire tribal economy was built about them. The mode of life, customs, and folk-lore of the Indians all centered about these animals. Their clothing and tepee covers were made of the skins. The tanned skins also served as individual and tribal records of the warrior-hunters, the chronicles being drawn in picture-writing on the smooth surfaces. The passing of the buffalo on the free sweep of the western plains ended forever one of the most picturesque phases of aboriginal life in America. =MUSK-OX= (=Ovibos moschatus= and its subspecies) The musk-ox is one of the unique and most interesting of American game animals. In general appearance it suggests a small, odd kind of buffalo, and is, in fact, related to both cattle and sheep. It is a heavily built, round-bodied animal, with short, strong legs and long fringelike hair which hangs so low on the sides that it sometimes trails on the snow. The horns--broad, flat, and massive at the base--curve down and out to a sharp point on each side of the head and form very effective weapons for defense. Fossil remains prove that musk-oxen lived in northern Europe and Asia during Pleistocene times, but they have long been confined to Arctic America. Up to within a century they have occupied nearly all of the cheerless wilds north of the limit of trees, from the coast of northern Alaska to that of east Greenland. They appear to have become extinct in northern Alaska within the last 75 years, and their present range east of the Mackenzie River is becoming more and more restricted. They are now limited to that part of the barren grounds of Canada lying north and northwest of Hudson Bay and from the Arctic islands northward and eastward to the northern coast of Greenland. Their range extends to beyond 83 degrees of latitude and covers some of the bleakest and most inhospitable lands of the globe. There a short summer, with weeks of continuous sunshine, permits the growth of a dwarfed and scanty Arctic vegetation; but winter brings a long period of night, continuous, in the northernmost parts, through several months.