Dean’s life began on February 22, 1935 in Jefferson, Ohio. He was the son of Stephen K. and Viola L. (Engel) Armstrong. He was a 1953 graduate of Blume High School in Wapakoneta, Ohio. Dean also served his country in the United States Army. Dean earned a Bachelor of Science degree in Engineering from Purdue University and a Master of Business Administration from the Harvard University School of Business. Dean had been employed by General Motors in Anderson, IN as the plant manager before moving to El Dorado with his wife Marilyn and his family in 1978. Dean joined his second Cousin Richard Teichgraber as owner of International Petroleum Services. After selling his share of International Petroleum Services, Dean purchased the Florence State Bank where he served as President and Owner. Dean owned several Florence businesses including Inlow Foam, Marion Insurance Company, Florence Funeral Home and a restaurant. He married a second time to Kathryn Park in September of 1988 in Sierra Vista, AZ. Dean moved to Marion in 2003 and was an avid golfer at Marion Country Club, he was very involved in the Florence Chamber of Commerce and was a Phi Delta Theta brother at Purdue University. Dean was especially instrumental in helping to encourage and develop business in Marion County. He was a trusted advisor and friend to many in the region and around the world. Dean’s greatest joy was his family which includes his wife Kate of Marion; children Ann (Tim) Heide of Austin, TX and Ellen (Mike) Egan of El Dorado; stepchildren Rhonda (Eldon) Hett of Marion, Bret (Randi) O’Dell of Peabody and Brenda (William) Clouse of Smithville, MO; grandchildren John Egan, Jaymie (Jesse) Adams, Ashton Heide and Olivia Heide; step-grandchildren Jerod (Natalie) and Justin (Brea) Hett, and Shawna (Albert) Johnson, step grandchildren Megan (Joel) Thomas, Alysha (Alex) Haines, Kellan and Keaton Clouse.; great grandchildren Easton, Nina and Ian Hett, Lilly, Otis and Guss Hett, Caileigh and Carlynn Johnson, Rylee and Clayton Thomas, and Tessa and Rhett Haines; his sister June (Dr. Jack Hoffman, M.D.) Hoffman of Phoenix, AZ and Wapakoneta, OH and nieces and nephews Jayne Hoffman, Jeffrey Hoffman, John Hoffman, Jacalyn Hoffman, Jodi Hoffman, Jenifer Hoffman, Jason Hoffman, Eric Armstrong and Mark Armstrong. Dean passed away on May 23, 2020 at St. Luke’s Hospital in Marion. He is preceded in death by his parents, sons Neil A. and Jay Armstrong and brother Neil Alden Armstrong, and niece Karen Armstrong. In accordance with Dean’s wishes there will be no public services. Yazel-Megli Funeral Home, Marion is serving the family. Memorial contributions in Dean’s name may be directed to the St. Luke’s Hospital Foundation or the Florence American Legion. Please sign his online guestbook and leave a memory of Dean at www.ymzfh.com.