March 22 – On this day in Montana History in 1870 word was spreading among early settlers of a herd of buffalo in the Milk River Valley that was migrating north. It was reported that the herd was virtually one mass of animals and that it took three days for them to move out of the valley. After it was gone, people reported that their trail was more than eight miles wide and that the ground was trodden to fine dust to a depth of six inches. By 1880 the wholesale slaughter of the Northern Great Plains herd was underway, and by 1886 buffalo were virtually wiped out in Montana and the West.