Dennis was born in Bay City, on July 18, 1948 to the late Bernard M. Mahoney and Gertrude A. (McFarland) Mahoney. He graduated from Bay City Visitation High School in 1966 and played football during his high school years. He attended Central Michigan University and transferred to Western Michigan University, graduating with a Bachelors of Science Degree in 1970. He earned a Masters Degree in Counseling from Western Michigan University and worked for the State of Michigan. His area of expertise was workers compensation. Dennis was an avid tennis, golf, volleyball and pickle ball player. He liked to travel and visit out of state family and friends.
He is survived by siblings, Michael (Blanche Fraser) of Fort Myers, FL, Mary (Thomas) Pawlak of Bay City, Patrick (Irene) Mahoney of Phoenix, AZ and Kevin (Genessa) Mahoney of Sierra Vista, AZ, loving companion, Ruth Pancoast of CO and many nieces and nephews.
At the request of Dennis, cremation has taken place and no services will be held at this time.