On May 29, 1805, the day after the midnight visit of the buffalo bull, Lewis documented one of the Indians' means of killing buffalo, sometimes called a buffalo jump, or "pishkun." To modern readers the practice may seem terribly wasteful, but in fact the Indians knew that if any animals escaped, the rest of the buffalo would soon learn to avoid humans, which would make hunting all the harder.
Today we passed on the Stard. side the remains of a vast many mangled carcases of Buffalow which had been driven over a precipice of 120 feet by the Indians and perished; the water appeared to have washed away a part of this immence pile of slaughter and still their remained the fragments of at least a hundred carcases they created a most horrid stench.
In this manner the Indians of the Missouri distroy vast herds of buffaloe at a stroke; for this purpose one of the most active and fleet young men is scelected and (being) disguised in a robe of buffaloe skin, having also the skin of the buffaloe's head with the years and horns fastened on his head in form of a cap, thus caparisoned he places himself at a convenient distance between a herd of buffaloe and a precipice proper for the purpose, which happens in many places on this river for miles together;
The other indians now surround the herd on the back and flanks and at a signal agreed on all shew themselves at the same time moving forward towards the buffaloe; the disguised indian or decoy has taken care to place himself sufficiently nigh the buffaloe to be noticed by them when they take to flight and runing before them they follow him in full speede to the precepice, the cattle behind driving those in front over and seeing them go do not look or hesitate about following untill the whole are precipitated down the precepice forming one common mass of dead an mangled carcases;
The (Indian) decoy in the mean time has taken care to secure himself in some cranney or crivice of the clift which he had previously prepared for that purpose.
The part of the decoy I am informed is extreamly dangerous, if they are not very fleet runers the buffaloe tread them under foot and crush them to death, and sometimes drive them over the precepice also, where they perish in common with the buffaloe.