Ojibwa Indians are gillnetting and spearing this spring, under rights first granted in 1837. After a long court battle, the Mille Lacs and other tribes were given authority to regulate their own hunting and fishing in a large section of east-central Minnesota -- including Lake Mille Lacs, the state's most popular walleye lake. It is a historic spring for the tribes -- and a dark one for treaty opponents, who still hope the Supreme Court will take up their cause. Leif Enger retraces the eight-year dispute. The 161-year-old treaty is a short, simple document -- you could read it twice before this story's over. In plain language, the Ojibwa yield t