Wilfred is buried in Cottonwood Catholic Cemetery in Cottonwood, Idaho.
Sources
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:VY4L-RN9 : accessed 15 November 2015), Wilfred Mader in household of Joseph Mader, Cottonwood, Cottonwood Election Precinct, Idaho, Idaho, United States; citing enumeration district (ED) 25-6, sheet 3A, family 42, NARA digital publication T627 (Washington, D.C.: National Archives and Records Administration, 2012), roll 747.
"United States Social Security Death Index," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VMW9-42L : accessed 15 November 2015), Wilfred A Mader, 13 Dec 2006; citing U.S. Social Security Administration, Death Master File, database (Alexandria, Virginia: National Technical Information Service, ongoing).