Thief River Falls – Tamara “Tammy” Ray-Ann Mattern, the daughter of Richard and Cheryl (Kvame) Kostrzewski, was born on September 20, 1967, in Thief River Falls. She died unexpectedly at the age of 55 years at her home on Saturday, April 29, 2023, in Willow City, North Dakota.
Tammy was born and raised in Thief River Falls, where she also graduated from high school and was 1st Chair Violin in the orchestra. After high school, she lived in Colorado and Michigan for a short time before moving to Fargo. While living in Fargo, she met LeRoy Mattern. On July 27, 1991, she and LeRoy were united in marriage in Thief River Falls. The couple made their home in Fargo and were blessed with three children, Tyler, Jesse and Aleah. Tammy worked at AmeriPride, while living in Fargo. In 2009, the family moved to Willow City and took over Mattern Family Meats in Bottineau, which they still run today.
Tammy enjoyed reading, gardening, baking, always wanting to try new recipes, ‘80s rock music, which her
children will never forget, collecting books and CDs. She loved her cats and dog, following her children’s many interests and sporting events. She was blessed in her life, loved her family more than anything, was proud to become a grandma and was so proud of her children. Her husband, children and family will miss her dearly.
Tammy is survived by her husband, LeRoy of Willow City; children, Tyler (Jocelyn) of Minot, Jesse and Aleah of Willow City; grandson, Malakai of Minot and one grandchild on the way; Father Richard Kostrzewski of Thief River Falls; siblings, Carl (fiancé Taryn Hoverson), Erica (Dale) Opdahl, Romayne Kostrzewski-Srnsky-Wilson,
Angie Poole, Wendy Bakken, all of Thief River Falls and Melony (Rolli) Burger of Lindstrom,; mother-in-law, Ilene Mattern of Rugby; brothers-in-law, Vince, Lawrence (Debbie) and Steven (Vita), all of Rugby; many nieces, nephews; other relatives and friends. She was preceded in death by her mother, Cheryl; step-mother, Maryls; father-in-law, Claytus Mattern and brothers-in-law, Wes Srnsky and Mike Wilson.
Casket Bearers: Carl Kostrzewski, Matthew Mattern, Steven Mattern, Matt Opdahl, Austin Opdahl and Roy Sourdif.
Funeral services will be held at 11:00 a.m. Tuesday, May 9th at First Lutheran Church in Willow City with burial in the Little Flower Catholic Cemetery in Rugby. Wally Fretland, officiating.
Visitation will be from 5:00 to 7:00 p.m. Monday with the reciting of the Holy Rosary at 7:00 p.m. followed by a prayer service and sharing of memories at the Anderson Funeral Home in Rugby. Visitation will continue on Tuesday for one hour prior to the services at the church.
Arrangements made with the Anderson Funeral Home of Rugby. Online registry: (www.funeralsbyanderson.com).
Anderson Funeral Homes
of Rugby & Towner located at 119 3rd Street SW ∙ Rugby, North Dakota, 58368.and phone (701)776-6381 and fax at (701)776-5916.

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