"Idaho Marriages, 1878-1898; 1903-1942," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:FW64-Q5T : 10 February 2018), Walter Tregellas and Rozella Morris, 18 Oct 1916; citing reference ; FHL microfilm 1,548,800.
"United States Census, 1920," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MDC1-Y1R : accessed 27 January 2019), Walter Tregellas, Wardner, Shoshone, Idaho, United States; citing ED 173, sheet 1A, line 33, family 9, NARA microfilm publication T625 (Washington D.C.: National Archives and Records Administration, 1992), roll 294; FHL microfilm 1,820,294.
"United States Census, 1930," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XCQW-V2Q : accessed 27 January 2019), Walter Tregellas, Spokane, Spokane, Washington, United States; citing enumeration district (ED) ED 33, sheet 18A, line 7, family 214, NARA microfilm publication T626 (Washington D.C.: National Archives and Records Administration, 2002), roll 2516; FHL microfilm 2,342,250.
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:K93V-5RW : 14 March 2018), Walter Tregellas in household of Raymond Tregellas, Area B, Spokane, Spokane City, Spokane, Washington, United States; citing enumeration district (ED) 41-14, sheet 9A, line 23, family 186, Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012, roll 4384.