He passed away in Shasta County, California in 1969.
Warren is buried at the Redding Memorial Park in Redding, Shasta County.
Sources
"United States Census, 1900," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M9VJ-FB1 : accessed 6 December 2020), Warren Haas in household of Charles Haas, Roscoe, Russell, Saratoga, Banner, Kinnison & Mikkelson Townships & Schools, LaMoure, North Dakota, United States; citing enumeration district (ED) 85, sheet 6B, family 124, NARA microfilm publication T623 (Washington, D.C.: National Archives and Records Administration, 1972.); FHL microfilm 1,241,229.
"Canada, Northwest Provinces Census, 1906," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:KHV6-GBC : 1 April 2016), Warren Haas in household of M Haas, 8, Strathcona, Alberta, Canada; Public Archives, Ottawa, Ontario.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XCN1-TJK : accessed 6 December 2020), Warren Haas in household of Chas R Haas, Shingletown, Shasta, California, United States; citing enumeration district (ED) ED 15, sheet 1B, line 61, family 21, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 220; FHL microfilm 2,339,955.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XCJM-F97 : accessed 6 December 2020), Warren M Haas in household of Patty J Hamilton, Township 5, Shasta, California, United States; citing enumeration district (ED) ED 16, sheet 2A, line 35, family 43, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 220; FHL microfilm 2,339,955.
"United States Social Security Death Index," database, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:J116-Q38 : 4 December 2020), Warren Haas, Feb 1969; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).
"California Death Index, 1940-1997," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VGRY-F9H : 26 November 2014), Warren M Haas, Shasta, California, United States, 26 Feb 1969, Mother's Name: Underwoo, Birth Date: 11 Jul 1894, Birthplace: Missouri; Department of Public Health Services, Sacramento.
Find a Grave, database and images (https://www.findagrave.com/memorial/98197060/warren-maxim-haas : accessed 05 December 2020), memorial page for Warren Maxim Haas (11 Jul 1894–26 Feb 1969), Find A Grave: Memorial #98197060, citing Redding Memorial Park, Redding, Shasta County, California, USA ; Maintained by Neal Underwood (contributor 47580240).