For this species seems to have become differentiated into several species and sub-species, some of which are well marked, and all of which we do not as yet know much about.  These as described are the common sheep of the Rocky Mountains (Ovis canadensis); the white sheep of Alaska (Ovis dalli), and its near relative, O. dalli kenaiensis; the so-called black sheep of northern British Columbia (O. stonei), described by Dr. Allen; Nelson’s sheep of the southwest (O. nelsoni) and O. mexicanus, both described by Dr. Merriam.  Besides these, Mr. Hornaday has described Ovis fannini of Yukon Territory, about which little is known, and Dr. Merriam has given the sheep of the Missouri River bad lands sub-specific rank under the title O.c. auduboni.  Recently Dr. Elliot has described the Lower California sheep as a sub-species of the Rocky Mountain form under the name O.c. cremnobates.  For twenty-five years I heard of a black sheep-like animal in the central range of the Rocky Mountains far to the north, said to be not only black in color, but with black horns, something like those of an antelope, but in shape and ringed like a female mountain sheep.  From specimens recently examined at the American Museum of Natural History, I now know this to be the young female of Ovis stonei.  That several species of sheep should have been described within the last three or four years shows, perhaps as well as anything, how very little we know about the animals of this group.

The sheep of the Rocky Mountains and of the bad lands (O. canadensis and O. canadensis auduboni) are those with which we are most familiar.  Both forms are called the Rocky Mountain sheep, and from this it is commonly inferred that they are confined to the mountains, and live solely among the rocks.  In a measure this belief is true today, but it was not invariably so in old times.  As in Asia, so in America, the wild sheep is an inhabitant of the high grass land plateaus.  It delights in the elevated prairies, but near these prairies it must have rough or broken country to which it may retreat when pursued by its enemies.  Before the days of the railroad and the settlements in the West, the sheep was often found on the prairie.  It was then abundant in many localities where to-day farmers have their wheat fields, and to some extent shared the feeding ground of the antelope and the buffalo.  Many and many a time while riding over the prairie, I have seen among the antelope that loped carelessly out of the way of the wagon before which I was riding, a few sheep, which would finally separate themselves from the antelope and run up to rising ground, there to stand and call until we had come too near them, when they would lope off and finally be seen climbing some steep butte or bluff, and there pausing for a last look, would disappear.