On the weekend of June 10-12, the Yakama Nation commemorated the Treaty of 1855. A brief history note: The treaty was signed on June 9, 1855. The tribe is the biggest reservation in Central Washington, with 11,000-plus enrolled members and situated on 1.1 million acres. The weekend kicked off with a parade in Toppenish and a softball tournament. The Pow Wow was in White Swan.