In the early 1700s, evolutionary changes in travel gave way to a major revolution when horses generally became available to the northwest tribes. It cannot be emphasized enough how dramatically the horse altered both transportation history and tribal culture. By the time Lewis and Clark came through the Bitterroot Mountains in 1805-06, the changes caused by horses were well established. It was now possible to travel great distances with enough food, shelter, and weaponry to make the journey as safe as it could be during those times. Food sources which were impractical before the horse now became routinely available. For example, horses enabled the hunting of buffalo over distances of hundreds of miles. The buffalo became a major food source in addition to providing robes, lodges, and bone tools, as well as many minor conveniences and personal adornments.
Horses facilitated both wider trade opportunities over much larger distances and the development of friendships with other, more distant, tribes. Trade routes were eventually established that made it possible for goods to travel hundreds of miles and change hands among several tribes between source and destination. For example, the Nez Perce of the Clearwater River established both trade and friendships with the Salish of the Bitterroot Valley and the Crows of the Yellowstone Valley.
The horse changed individual family life as well. The shorter travel times made practical the establishment of marriages and alliances between members of tribes separated by several hundred miles. Before the horse, travel on foot had limited the mobility of families and larger groups. With horses, great distances could be traveled with relatively good speed and safety. It is entirely understandable that Lewis and Clark observed that families greatly valued their horse herds.
However, the horse also brought more widespread warfare among northwest tribes. Raiding and horse stealing became part of a young man's initiation into adulthood and preparation for chieftainhood in many tribes. We see the beginning of "war trails" extending all the way from North Dakota to Idaho and Washington. It was this stage in the evolution of tribal culture that was witnessed by European explorers during their first contacts with the northwest tribes.
Another change brought about by the horse was a revolution in the nature of the trails across the Bitterroot Mountains. Trails traveled by horses needed to be fundamentally different from those for foot traffic. This often meant a location change for better safety and navigability. Horse trails also needed to pass by the water and food sources necessary to sustain the horses over long journeys.
The physical characteristics of the trails also changed. Where soft feet once traveled with hardly a trace of their passage, the sharp, heavy hooves of horses cut into the soil, creating an ever deepening and widening erosion trace that can still be found today—more than two hundred years later. For example, the Northern Nez Perce Trail along the Lolo Trail route is still more than two feet deep in several places.
The Northern Nez Perce Trail was the old horse trail followed by Lewis and Clark in 1805-06. By that time, it had been used for decades and was deeply eroded in the steeper locations. Lewis and Clark referred to it as the "great road" in the journals because of its importance to travelers of that time. This was the original Lolo Trail. Besides all of these differences, horse trail locations had some things in common with the early foot paths. They still followed the extensive ridge systems across the mountains and they were still located on the ridge tops and ridge shoulders with snowmelting southern exposures. Also, the ridges still needed to be burned for easier and more secure travel.
Funded in part by a grant from the Idaho Governor's Lewis and Clark Trail Committee