This primary source comes from the Records of the Bureau of the Census.
Full Citation: 113th Congress of the United States, Washington State Map; 2010; [Decennial] Census of Population and Housing, 2010: Thematic Maps, Large Sheet Maps; Thematic Maps from the 23rd Census of Population and Housing, 2010 - 2010; Records of the Bureau of the Census, Record Group 29; National Archives at College Park, College Park, MD. [Online Version, https://www.docsteach.org/documents/document/113th-congress-of-the-united-states-washington-state-map, October 14, 2024]