This road along today’s Clark Fork River was part of a wide-ranging aboriginal trail system that crossed the Continental Divide to reach buffalo hunting grounds centered at the headwaters of the Missouri and Yellowstone rivers. Following water level, it made travel less difficult, especially in winter when mountain passes were filled with snow, and it was used by numerous tribes, often traveling together, including the Salish, Coeur d’Alene, Pend d’Oreille, Kalispel, Kootenai, Spokane, Nez Perce, and other Columbian Plateau groups. In 1809, North West Company explorer and agent David Thompson recorded that he was following the Saleesh Road to the Buffalo when he passed near here while returning to the Big Bend of McGillivray’s River, today’s Kootenai, to intercept his clerk, James McMillan, who was bringing canoes loaded with trade goods and supplies for Thompson’s new trading posts. At Horse Plains, W.A. Ferris wrote in 1833 that a village of Indians collected there who never went for buffalo, while in 1857 Indian Agent R.H. Lansdale wrote that they went to buffalo twice a year, first “to bulls” and second “for cows.” Few areas of the original tread remain, but years of foot and horse travel created the classic U-shaped roadbed. Alexander Ross of the Hudson’s Bay Company left Prairie de Cheveaux, or Horse Plains, in February 1824 on his Snake River Expedition and recorded 67 men with 20 lodges; using David Thompson’s estimate of 7 individuals to a lodge, there were roughly 200 individuals in Ross’s party, along with more than 230 horses, though this was a small group compared with the combined tribes and horses traveling to the buffalo hunting grounds.