At least twice, this place drew enormous gatherings to negotiate treaties that transformed relations among Indian tribes and opened the way for Euro-American entry into Montana. In September 1846, Jesuit missionary Father Pierre Jean DeSmet brokered a peace between the Blackfeet and Flathead, whose warfare had allowed the Crow to prey on both tribes during long-standing competition over buffalo hunting grounds. Nine years later, Isaac S. Stevens, Governor of Washington Territory, was charged with negotiating a treaty to allow safe exploration and settlement by pioneers along the Missouri River. At least 15,000 Blackfeet, Nez Perce, and Flathead gathered here for 10 days, and the Stevens Treaty was signed on October 17, 1855. The Blackfeet called it Lame Deer's Treaty after their chief negotiator. It defined Blackfeet homeland as a large portion of present-day Montana east of the Rockies, including most land north of the Missouri River and most land north and west of the Musselshell River. Within that area, other tribes could hunt buffalo once each year, while the U.S. Government could establish trade routes and developments such as forts and telegraph lines needed to support navigation along the Missouri River. Natawista, of the Blood tribe of the Blackfoot Confederacy and wife of Fort Benton founder Alexander Culbertson, was thought to have played a pivotal role in the successful negotiations of the 1855 treaty and was likely responsible for the success of many of her husband's endeavors to promote good relations between Indians and Euro-Americans.