Dennis was born on January 17, 1939, in Browerville to George and Helen (Becker) Biermaier. On November 27, 1961, Dennis married Doris Sowada, the love of his life at Our Lady of Lourdes Church in Little Falls. They purchased their farm in 1966, which he loved and there were many memories made over the years. He enjoyed spending time with family and friends. He especially loved to dance and play cards. They recently celebrated 60 years of marriage. 

Dennis worked at the Milk Plant in Browerville for some years and then retired from Harts Press/ Banta in 2001 after 37 years. Dennis served in the Minnesota National Guards for ten years and was honorably discharged in 1958.

Dennis is survived by his wife Doris, children, Jill (Tom) Dempsey, Lori (Gerald) Martin, Neal (Priscilla) Biermaier. Seven grandchildren, Jenny (Ben) Frieler, Derek Dempsey, Zach, Megan and Hannah Martin, Jake (Jasmine) Biermaier and Lexi Biermaier. 5 great grandchildren and one on the way. Siblings Louis (Pat) Biermaier, Sister Ann Marie Biermaier OSB, Ron (Sherry) Biermaier, and Karen (Daryl) Brever. 

He is preceded in death by his parents George and Helen Biermaier, in-laws Leonard and Ida Sowada and sister-in-law Laverne Biermaier.