At the time of the great division made by the Union Pacific Railway the northern body of buffalo extended from the valley of the Platte River northward to the southern shore of Great Slave Lake, eastward almost to Minnesota, and westward to an elevation of 8,000 feet in the Rocky Mountains. The herds were most numerous along the central portion of this region (see map), and from the Platte Valley to Great Slave Lake the range was continuous. The buffalo population of the southern half of this great range was, according to all accounts, nearly three times as great as that of the northern half. At that time, or, let us say, 1870, there were about four million buffaloes south of the Platte River, and probably about one million and a half north of it. I am aware that the estimate of the number of buffaloes in the great northern herd is usually much higher than this, but I can see no good grounds for making it so. To my mind, the evidence is conclusive that, although the northern herd ranged over such an immense area, it was numerically less than half the size of the overwhelming multitude which actually crowded the southern range, and at times so completely consumed the herbage of the plains that detachments of the United States Army found it difficult to find sufficient grass for their mules and horses.[67] [Note 67: As an instance of this, see _Forest and Stream_, vol. II, p. 184: "Horace Jones, the interpreter here [Fort Sill], says that on his first trip along the line of the one hundredth meridian, in 1859, accompanying Major Thomas--since our noble old general--they passed continuous herds for over 60 miles, which left so little grass behind them that Major Thomas was seriously troubled about his horses."] The various influences which ultimately led to the complete blotting out of the great northern herd were exerted about as follows: