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1951 Marc 2020

Marc John Dettmann

April 3, 1951 — October 21, 2020

On the 21st of October 2020, Marc John Dettmann, a loving husband, and father of four children passed away at the age of 69.  Marc was born April 3, 1951, in West Allis, WI to Karl and Beverly Dettmann, the second of five children. 

Marc received his B.A. from Luther College before attending the Wharton School of the University of Pennsylvania where he received his master’s in business administration and graduated Summa Cum Laude.  Marc then received his Juris Doctor degree from Harvard University.  While at Harvard, Marc met the love of his life, Mary Elizabeth Gallagher, and married her on October 6, 1979. 

While Marc’s early career focused on practicing law, he found a passion for healthcare management and joined the Mayo Clinic in its health administration.  Marc spent the remainder of his career in the health sector, working for the University of Wisconsin Health System before retiring as the Chief Executive Officer of the University of Virginia Health Services Foundation.

Marc had a passion for the arts and sports.  Growing up, he won many state and national awards for science, math, and art. He continued his passion for art into adulthood, using his time in retirement to paint when possible.  In addition, Marc was an avid baseball fan and loved to cheer on the Chicago Cubs, Chicago White Sox, and Milwaukee Braves – now Brewers. 

Marc was a lifelong collector of stamps, coins, baseball cards, and scripophily (collecting signatures from historically significant people). He was a skilled woodworker and constructed beautiful furniture for his home. He enjoyed model trains and would often build trains from scratch.

Marc was preceded in death by his father, Karl, and mother, Beverly.  He is survived by his wife Mary, four children, Andrew, Kathleen, Bridget, and Ryan; brothers, David, Scott, and Paul, sister, Yvonne; and four grandchildren. 

A special thank you to the Innovations staff at Rosewood Village Hollymead and Riley from Home Instead for their kind care during Marc’s battle with Parkinson’s Disease and Lewy Body Dementia. 

A visitation will be held at Ryan Funeral Home on Sunday, October 25, 2020, from 2 pm -3 pm followed by a memorial service from 3 pm - 4 pm.  Social distancing and mask requirements will be requested for the service.  A funeral service will be held at New Horizons United Church of Christ in Boltonville, Wisconsin at 1:00 PM on Saturday, October 31, 2020. Interment will follow at Boltonville Union Cemetery located on Bolton Drive Kewaskum, WI.

In lieu of flowers please feel free to make memorial contributions to Hospice of the Piedmont, Parkinson’s Foundation, Lewy Body Dementia Association (LBDA), or a charity of your choice.

Ryan Funeral Home of Ruckersville, VA is handling memorial arrangements.

An online guest book is available at 

To order memorial trees or send flowers to the family in memory of Marc John Dettmann, please visit our flower store.

Service Schedule

Past Services

Memorial Visitation

Sunday, October 25, 2020

2:00 - 3:00pm (Eastern time)

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Memorial Service

Sunday, October 25, 2020

3:00 - 4:00pm (Eastern time)

Enter your phone number above to have directions sent via text. Standard text messaging rates apply.

Funeral Service

Saturday, October 31, 2020

Starts at 1:00pm (Eastern time)

New Horizon United Church of Christ

9663 State Hwy 144, Kewaskum, WI 53040

Enter your phone number above to have directions sent via text. Standard text messaging rates apply.


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