In 1867, when Maj. J. W. Powell and Prof. A. H. Thompson crossed the plains by means of the Union Pacific Railway as far as it was constructed and thence onward by wagon, they saw during the entire trip only one live buffalo, a solitary old bull, wandering aimlessly along the south bank of the Platte River. The completion of the Union Pacific Railway divided forever the buffaloes of the United States into two great herds, which thereafter became known respectively as the northern and southern herds. Both retired rapidly and permanently from the railway, and left a strip of country over 50 miles wide almost uninhabited by them. Although many thousand buffaloes were killed by hunters who made the Union Pacific Railway their base of operations, the two great bodies retired north and south so far that the greater number were beyond striking distance from that line. 5. _The destruction of the southern herd._--The geographical center of the great southern herd during the few years of its separate existence previous to its destruction was very near the present site of Garden City, Kansas. On the east, even as late as 1872, thousands of buffaloes ranged within 10 miles of Wichita, which was then the headquarters of a great number of buffalo-hunters, who plied their occupation vigorously during the winter. On the north the herd ranged within 25 miles of the Union Pacific, until the swarm of hunters coming down from the north drove them farther and farther south. On the west, a few small bands ranged as far as Pike's Peak and the South Park, but the main body ranged east of the town of Pueblo, Colorado. In the southwest, buffaloes were abundant as far as the Pecos and the Staked Plains, while the southern limit of the herd was about on a line with the southern boundary of New Mexico. Regarding this herd, Colonel Dodge writes as follows: "Their most prized feeding ground was the section of country between the South Platte and Arkansas rivers, watered by the Republican, Smoky, Walnut, Pawnee, and other parallel or tributary streams, and generally known as the Republican country. Hundreds of thousands went south from here each winter, but hundreds of thousands remained. It was the chosen home of the buffalo." Although the range of the northern herd covered about twice as much territory as did the southern, the latter contained probably twice as many buffaloes. The number of individuals in the southern herd in the year 1871 must have been at least three millions, and most estimates place the total much higher than that.