The range of the buffalo or bison in the United States formerly extended from Great Slave Lake on the north to the northeastern provinces of Mexico on the south--from 62° latitude to 25°. Its westward range extended beyond the Rocky mountains and embraced quite a large area, remains having recently been discovered as far west as the Blue mountains in Oregon; farther south, herds roamed over the region occupied by the Great Salt Lake basin and grazed westward as far as the Sierra Nevada mountains. East of the Rocky mountains the feeding-grounds embraced all the area drained by the Ohio river and its tributaries, extending southward beyond the Rio Grande and northward to the Great Lakes as far as the eastern extremity of Lake Erie. The southeastern range probably did not extend beyond the Tennessee river, and only in the upper portions of North and South Carolina did it extend beyond the Alleghanies. The habitat of the buffalo included feeding-grounds, stamping-grounds, wallows and licks. Their feeding-grounds embraced the meadow valleys where the choicest grazing was to be found.[92] The habit of keeping together in immense herds while feeding soon exhausted the food in any single locality and rendered a slow, constant movement necessary. A herd so immense that it remained in the sight of a traveler for days required a vast area of feeding-ground to sustain it during a season. When a herd rested to ruminate the buffaloes arranged themselves in a peculiar, characteristic manner--the young always in the center with the mothers, the males forming a compact circle around them. By such a conformation were the "stamping-grounds" made--each animal crowding and pushing from the outside of the herd, where flies and insects were more troublesome, toward the center. A peculiar custom of the buffalo was "wallowing." In the pools of water the old fathers of the herd lowered themselves on one knee, and with the aid of their horns, soon had an excavation into which the water trickled, forming a cool, muddy bath. From his ablutions each arose, coated with mud, allowing the patient successor to take his turn. Each entered the "wallow," threw himself flat upon his back, and, by means of his feet and horns, violently forced himself around until he was completely immersed. After many buffaloes had thus immersed themselves and, by adhesion, had carried away each his share of the sticky mass, a hole two feet deep and often twenty feet in diameter was left, and, even to this day, marks the spot of a buffalo wallow. The "delectable laver of mud" soon dried upon the buffalo and left him encased in an impenetrable armor secure from the attacks of insects.