Born March 3, 1840, Hinmatóowyalahtq̓it, often translated as “Thunder Rolling Down the Mountain,” was the son of the Wal-am-wat-kain/Wallowa leader Tuekakas, also known as Old Joseph. Both were baptized with the Christian name Joseph. Though his father supported the 1855 treaty and initially welcomed relations with the United States, settlers soon encroached, often violently, and the United States failed to enforce its own treaty. Old Joseph advised his son to protect the lands of their ancestors and not give it to anyone. In 1871, after his father’s passing, Chief Joseph took up his father’s role as leader. Though he promised to follow his father’s words, violence toward his people and a lack of legal recourse made it difficult to protect the people and remain on the land. In 1873, he negotiated an agreement with the federal government to allow his people to remain in the Wallowa Valley, but by 1877, the government reversed this policy, sending General Howard with an eviction notice.

Chief Joseph met with Howard in May 1877 and refused to agree. When Howard told him that staying beyond his 30-day notice would be considered an act of war, Chief Joseph prepared his people to leave the Wallowa Valley.