From 1866 to 1868, Indian councils were held at Fort Rice, including a Great Council with Sioux bands in July 1866. Thathanka Iyotake, or Sitting Bull, refused to participate, but Father Pierre Jean De Smet persuaded him to allow his chief lieutenant, Phizi, or Gall, to attend. Sioux bands then signed the Fort Laramie Treaty of 1868, ending the Red Cloud War and defining the Great Sioux Reservation, which included most of the area west of the Missouri River in present-day South Dakota. Fort Rice was rebuilt in 1868 with more suitable materials and served another ten years with detachments. Between 1871 and 1873, it was the base for three Yellowstone expeditions that escorted surveying parties along the route of the Northern Pacific Railroad. Four companies from Fort Rice's contingent of the 7th Calvary accompanied Lieutenant Colonel George A. Custer on the Black Hills expedition in 1874, and two companies fought in the Battle of the Little Bighorn. Fort Rice was decommissioned on November 25, 1878, after Fort Yates was established at the Standing Rock Agency. Material from the fort became part of Fort Abraham Lincoln farther north on the Missouri River in Dakota Territory. In 1913, the State of North Dakota acquired Fort Rice, and in the 1940s the Works Progress Administration marked the foundations of many of the buildings on the site.