Mary Elizabeth Theiss: December 2, 1931 – June 26, 2026

DEER ISLAND- Mary Elizabeth Theiss, our loving daughter, sister, wife, mother, grandmother and aunt, died June 26, 2026, age 94.

Mary was born December 2, 1931 to Manuel and Laura (Mendonca) Costa, in Chico, California, the only daughter and last of four children. Throughout her life, Mary was lovingly called “Sis” by Louis, Leonard, and Donald and their wives Helen, Rita and Yvonne. Mary’s first marriage to Warren Gravelle, produced four children – three sons and a daughter – Paul, Martin, Eric and Ann. She was a loving and attentive homemaker to her children. Like her mother before her, she excelled at putting a tasty meal at the table, always perfectly seasoned and served with love.

Mary married William Theiss in 1987. Mary became the loving matriarch of a blended family. In 1995 they moved to Oregon, settling in Deer Island where they built a beautiful home and garden. Mary loved being a member of the local gardening club. It was here that Mary lived out her final years, accompanied by Bill, surrounded by her gardens, and visited by her friends and family.

Mary was preceded in death by her sons Paul and Martin, her first husband Warren, and all of her beloved brothers and sisters-in-law. Left to mourn her passing are her husband of over 40 years, Bill; her son Eric Gravelle and wife Leesa, daughter Ann Hardesty and husband Clair; step-sons, Anthony, Edward and his wife Lada; and Steve and his husband Thom. Mary had many grandchildren and great-children whom she enjoyed. Also mourning are nieces and nephews, many of whom counted Mary as their favorite aunt.

Mary’s services will be held on Monday, July 13, 2026 at the Columbia Funeral Home in St. Helens, Oregon. Viewing begins at noon, followed by a service at one o’clock. Graveside services just after at Columbia Memorial Gardens.