Supplemental treaty between the United States of America and the confederated tribes and bands of Indians of middle Oregon. Concluded November 15, 1865. Ratification advised March 2, 1867. Proclaimed March 28, 1867.

Published text of a supplement to the Treaty of June 25, 1855 that established sovereignty for many nations on the Columbia Plateau. The supplement establishes specific rights and restrictions by those governed by the Treaty of 1855, including the right to hunt, fish, and gather on one's reservation. The treaty was ratified in 1867 under President Andrew Johnson.