This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
530802Full Citation: Photograph 111-SC-82381; Bird's Eye View of Sioux Camp at Pine Ridge, South Dakota; 11/28/1890; Photographs of American Military Activities, ca. 1918 - ca. 1981; Records of the Office of the Chief Signal Officer, Record Group 111; National Archives at College Park, College Park, MD. [Online Version, https://www.docsteach.org/documents/document/sioux-camp-pine-ridge, May 12, 2024]