First Peoples Buffalo Jump State Park, formerly known as Ulm Pishkun, is an archaeological site with possibly the largest bison cliff jump in North America. Native peoples used this site for at least two thousand years prior to Lewis and Clark's expedition through Montana. The kill site consists of a mile long sandstone cliff; there are remnants of drive lines on top of the cliff and the remains of millions of 'processed' bison below. The process of tricking the bison was done before 1730 when Plains Indians did not have horses; a successful hunt require the coordinated work of all members of the tribe. The buffalo was sacred to the Plains Indians; the result of the annual kill resulted in the starvation or survival of the tribe.