Mary Helen Rotenberger

Mary Helen Rotenberger, 90, formally of Detroit Lakes, MN passed away in her sleep Tuesday, February 3, 2026, at Huntington Retirement Hotel in Torrance, CA. Mary was born April 14, 1935, in Mayville, ND to Henry and Hilda (Sydow) Grothmann. Mary grew up in Blanchard, ND and graduated from Hillsboro High School. 

After graduating high school, Mary moved to Fargo to work for “The Store Without a Name” and Northwest Bell Telephone. Mary was united in marriage to Ed Rotenberger at St. John’s Lutheran Church in Hillsboro, ND, August 27, 1958. Mary and Ed lived in Hawaii from 1958-1960 while Ed was stationed in the Army. After Ed was honorably discharged from the Army, they moved back to Fargo and in 1964 they moved to Detroit Lakes, MN. Mary worked for the Detroit Lakes Schools District as a School Aide, Librarian, and School Secretary from 1969 until her retirement in 2000. Mary was an active member of Zion Lutheran Church and served as a Sunday School Teacher, Church Secretary and Wedding Coordinator for many years; along with being active in LWML. She was also involved with Detroit Lakes Mrs. Jaycees serving as Secretary, VP and President, along with Regional State VP. In addition, she was active in 4-H, Cub Scouts and Camp Fire Girls with her children. In her spare time, she enjoyed reading, sewing and crafting. 

She is survived by her two children: Scott (Beatrice) and their children, Eric and Lauren of Redondo Beach, CA and Denise (Nick) Relich of Littleton, CO and their daughter Nicole of Castle Rock, CO. She is also survived by her sister Ruth Johnson (Hillsboro, ND), Sister In-Law Sharon (Gerry) Radebaugh (West Fargo, ND) and Ed’s brother Ted and his wife Lois Rotenberger (Fargo, ND). 

She was preceded in death by her parents, brothers, Art, Warren and David Grothmann, and brother in-law James Johnson, in addition to Ed’s other siblings and their spouses.

Services to be conducted at Zion Lutheran Church of Detroit Lakes on Monday, February 16th, beginning with a time of visitation at 10am and formal services starting at 11am.  Burial will take place at Oak Grove Cemetery following a time of food and fellowship at the church.

A livestream webcast of the service may be viewed on Zion Lutheran Church's FaceBook page.  Her funeral service will also be livestreamed on this page (video player window below), but if unsuccessful it will be uploaded to this tribute page shortly after the service is completed..