A native of Minnesota, Mattson began his career in milling in 1946, joining Atkinson Milling Co. in Minneapolis, Minnesota, U.S. as a plant engineer. While with Atkinson, he guided that company to pioneer in the bulk delivery of flour, becoming plant manager in 1952. When Atkinson Milling was acquired by ADM Milling Co. in 1962, he joined ADM, and advanced to production manager of milling operations in 1966.
When Fred L. Merrill, who had been head of ADM Milling, left that position and in 1972 and founded Cereal Food Processors (CFP), he invited Mattson to join him, as the third member of the staff of the new company. This was before CFP, which is now a company with more than 100,000 cwts of daily milling capacity, had acquired its first flour mill. Starting as operations manager of CFP, he became executive vice-president in 1984 and vice-chairman of the board in 1989.
Mattson’s commitment to the advancement of flour milling was reflected in his long-time membership and participation in meetings of the International Association of Operative Millers (IAOM). His focus on flour milling efficiency combined with the highest levels of quality was legendary. In 1989, he was awarded the IAOM Special Award for Technical Committee Longevity. This award is now called the Thaddeus B. Bownik Outstanding Service award. In 2007, he was the Conference Honorary Chairperson for the IAOM meeting in Overland Park, Kansas, U.S.
Surviving are his wife, Harriett Mattson; two daughters, Barbara Renneke of Lakeville, Minnesota, U.S., and Gretchen Lally of Olsburg, Kansas, U.S., three grandsons and two granddaughters.
Memorial services will be held Dec. 4 at Leawood Presbyterian Church. The family prefers memorials to the church or to the Harvesters Community Food Network.