Katherine Mary Kratz, mother, wife, psychologist, insatiable traveler, fierce advocate for justice,
and wellspring of joy and laughter, died at age 71 of lymphoma in Cleveland, Ohio on
September 1st, 2026.
Katherine was born on May 4, 1955, in Peru, Illinois of parents Sally (McDiarmid) and Myron
Kratz. She earned a Bachelor of Science in Psychology at Western Illinois University, then
began a two year placement in the Peace Corps working in South Korea. At the conclusion of
her commitment, she embarked on a journey of discovery and adventure lasting three years and
crossing many countries in Asia, Africa, and Europe where she lived, worked, and explored.
Upon her return to the U.S., Katherine settled in St. Paul, MN. She soon enrolled in a Masters in
Educational Psychology program at the University of Minnesota. She worked as a study abroad
advisor for the University of Minnesota’s International Studies Institute, while volunteering at a
women’s reproductive and mental health center and in various social change movements
including and especially feminism. Upon earning her degree in Ed Psych in 1989, Katherine
secured a two-year fellowship at St. Paul’s Hamm Clinic to further develop her counseling skills.
In 1988, Katherine ate lunch at a Korean restaurant near campus with fellow graduate student
Mark Mattern. Soon afterward, they were sharing a home in south Minneapolis. They married on
September 22, 1990. Their son Leon arrived two years later. The family moved to Orange,
California in 1994 when Mark secured an academic position at Chapman University. Katherine
eventually began work on a PsyD in Clinical Psychology at Alliant International University in San
Diego, CA. The doctorate was awarded shortly after she and her family moved to Lakewood,
Ohio in 1999. She practiced at several different sites, eventually becoming a partner in Horizons
Counseling Services, Parma, Ohio.
Katherine’s commitment to social justice propelled her into many activist causes. Her love of
literature kept her glued to her favorite stuffed chair for hours on end, followed by spirited
discussions in her women’s book group and with other fellow readers. Katherine threw herself
into pickleball, developing rapidly as a player and meeting many new friends. Katherine loved to
join friends and family in lively conversation, and she had a gift for it. She was a great listener,
perhaps a skill developed through her work with therapy clients. Her sharp insights and quick wit
enlivened every conversation. Katherine developed countless close relationships with friends
and family who will miss her thoughtfulness, her wit, her cross-court pickleball dinks, her
enthusiastic voice at political rallies, and her loving support.
Katherine felt her deepest love for her son, Leon. When he was a young child, she would tuck
him in at night with the words, “I will always love you up to the sun and the moon, and the stars
and the planets.” Her many family members and friends now say the same to her: “We will
always love you up to the sun and the moon, and the stars and the planets.”
Katherine is survived by her son, Leon Kratz, her husband Mark Mattern, seven siblings and
their families including Sandy (Larry Garifo), Peter, John (Kate Molitor), Mary Beth, Carol (Drake
Hokanson), Sally Ann, and Amy; one aunt; and many nieces, nephews, and cousins. On the
Mattern side and not already mentioned, Katherine is survived by in-laws Pat and Patty (Leong)
Mattern, Kate (Mattern) and Craig Derickson, Ben and Maureen (Costello) Mattern, Mary
(Mattern) and Robert Gonderinger, Matt and Janice (Bially) Mattern, Elizabeth (Mattern) and
Rod Rhodes, and Bill, Jr. and Jean (Deveny) Mattern; and by numerous nephews, nieces, and
cousins.
Katherine was preceded in death by her parents, her brother Mark, and her sister Patty in
infancy.
A memorial celebration for family and friends will be held on Saturday, October 17, 2026 at 4:00
– 7:00 pm, with a brief program of remembrance commencing at 5:00 pm. The event will be held
at the Emerald Necklace Marina Scenic Valley Room, 1500 Cleveland Metro Park Drive,
Lakewood, Ohio 44107. In lieu of flowers, please instead consider making a donation to the
Cleveland Food Bank, where Katherine often volunteered, or to the American Civil Liberties
Union (ACLU), to which she often donated.