Charles Eli Mix
（重定向自Charles Mix）
Charles Eli Mix (February 4, 1810 – January 15, 1878) was an American civil servant. He served as Chief Clerk of the Bureau of Indian Affairs from 1838 to 1868. For a brief period in 1858, Mix was Commissioner of the Bureau of Indian Affairs. During his time as Commissioner, he oversaw the signing of a treaty with the Yankton Sioux Tribe of the Dakota Territory (present-day South Dakota). The Treaty of Washington was signed on April 19, 1858 and ratified by the United States Senate on February 16, 1859. Charles Mix County, South Dakota, organized in 1862, is named after him.