Carl Frederick Thomas Holter passed away on March 29, 2026, at Froedtert Hospital in Milwaukee, Wisconsin, following injuries sustained during a walk around Mauthe Lake—a place that, in many ways, said much about him and his humble reverence for life. He was 84 years old, and he spent every one of those years loving the people around him with a quiet, steady devotion that left no one who knew him in any doubt as to where they stood.

Carl was born on December 11, 1941, in Hatton, North Dakota, to Jerome and Esther Holter. He grew up in Hatton, where the family homestead was built by his father and the family and friends surrounding him were devout and loyal, values that stayed with him for the rest of his life. After high school, Carl graduated from the North Dakota State School of Science with an Industrial Drafting and Science degree in 1962 then got his first job as a draftsman at Beloit Corp in Beloit, Wisconsin, before serving in the United States Army stationed in Butzbach, West Germany (1964-1966), as a Battalion Draftsman in the 16th Signal Battalion. He returned home to earn his BS in Agricultural Engineering with a Mechanical Certificate from North Dakota State University, passing the Wisconsin examining board and obtaining his PE license in 1981.

He married his beloved wife Jan (Janet, née Hume) in 1967, and in 1970 they settled in Cedar Rapids, Iowa, where his engineering career began at FMC Corporation.

In 1975 he and Jan moved to Waukesha, Wisconsin, where together they built the house their family would grow up in. That house, the memories built in and around their life together, plus his faith in God, were all at the center of Carl's world.

He spent the bulk of his career as an engineer, moving through roles at Harnischfeger Corp and Kearney & Trecker Corp in Milwaukee before landing in 1983 at ABB Robotics in New Berlin, Wisconsin. He served as ABB’s Design Engineering Manager from 1985 to 1991. After retiring from ABB he ran his own design engineering consulting firm, Puzzleworks, from 2000 to 2016.

Over the course of his professional life he was awarded seven patents—a record of intellectual contribution that he wore with characteristic humility. His first came during his years at FMC, where he designed the Tower Crane (US Patent 4,159,776)—a hint of the inventive mind that would quietly shape his field for decades. Carl was the kind of engineer who solved problems

not for recognition, but because that's what you did: you showed up, you figured it out, and you made it work. He treated his friends and family with the same dedication, humility, and care.

In 2011, Carl and Jan moved to Jackson, Wisconsin, drawn closer to their grandchildren who had become the great joy of their golden years. When Jan passed in 2017 after a courageous battle with cancer, Carl carried the loss with the same grace he brought to everything—not without grief, but without bitterness. In 2019, he moved to Cedar Community Center, where life offered him something unexpected: a second love. He and Diane found each other there, and married in 2022, a reminder that Carl Holter was never a man who closed himself off from happiness. He spent his years at Cedar Community hiking, traveling, and enjoying life with Diane and her family: daughter Deb Beyer (Tim) and their son Johnathan of Hudson, Wisconsin; and son Scott Yarmark (Rich Laws) of Nevada City, California.

Outside of work, Carl was a man of his hands and his heart. He loved woodworking and took particular care in refinishing and gifting family heirlooms… objects that held memories, pieces that deserved to be honored. He loved puzzles. He loved birds, wildlife, walking in nature. He loved listening to Jan play the piano and lead worship at their churches and sharing the treasures he made with those he loved. And, more than almost anything, he loved the annual "cousins campouts” they would gather his grandchildren for… those unhurried, uncomplicated times when everyone he cherished was in the same place at once.

As Dad and Grandpa, Carl was known to be a jokester, often entering a room with a crazy outfit, hat or dance to make everyone smile and laugh. He was never looking to be the center of attention in any room he was in, but also didn’t have any problem claiming his chair as the jester in any room where he chose to share this side of himself!

Carl was one of eight children and is survived by his siblings Marilyn, Rick, Neal, and Michael; his wife Diane; and his three children and their families: Daniel Holter (Kate) of Seattle, Washington, and their children Elias, Samantha, and Grayson; Mark Holter (Shea) of San Diego, California, and their children Abigail (Mark) and Seth; and Joy Zaffke (Jamie) of Selbyville, Delaware, and their children Tyler and Isabella.

He leaves behind seven grandchildren who know exactly how much he loved them and how proud he was of each of them… because he made sure to let them know every chance he got.

Celebrations of Carl's life will be held at dates to be announced in the near future (in Wisconsin and North Dakota). He will be laid to rest alongside his parents in Hatton, ND.

He was preceded in death by his parents, Jerome and Esther Holter of Hatton, North Dakota; his wife of 50 years, Janet; and his siblings Gordon, Janice, and David.

Carl Frederick Thomas Holter was a man of kindness, integrity, faith and love. These were not abstract ideals to him, they were his daily practice. He showed up for his family. He did the work, quietly, humbly. He made people feel held, seen, respected and accepted.

He will be deeply, lastingly missed. He was, in every way that mattered, his family's greatest inheritance.

"Den største arven du gir, er hvordan du lever." — Norwegian proverb (the greatest legacy you leave is how you live)

Memorials in honor of Carl can be made out to a charity that he and Jan spent their entire lives supporting, Foundation For His Ministry (https://www.ffhm.org/).

Myrhum-Patten Funeral & Cremation Service has been entrusted with Carl’s arrangements. Additional information and guest book can be found at www.myrhum-patten.com.