 Congress in 1886 authorized the Secretary of the Interior to negotiate with the tribe, to gain their cession of all of their land outside the reservation.In 1887 the tribe and the federal government came to an agreement under those terms, but Lake Coeur d'Alene and related waters were part of the reservation.In 1889, the tribe ceded the northern third of the reservation back to the federal government, including part of Lake Coeur d'Alene, for compensation.