Mary Janice O'Neill

Mary Janice O’Neill, beloved mother, grandmother, and friend, passed away peacefully on September 24, 2025, at the remarkable age of 101 and a half. Born on March 6, 1924, in Greenfield, Iowa, to her devoted parents Glen and Nelli Plymesser, Mary’s life was one of joy, resilience, and love.

After attending Boulder High School, Mary married the love of her life, John O’Neill, on March 8, 1948. Together, they built a beautiful life filled with adventure, laughter, and devotion to family. Their journey began in Panama, then Colorado where they welcomed their first daughter, Patricia (Patty) Nelson, and later took them to New Jersey to be near John’s family, where their second daughter, Barbara Pike, was born.

Mary loved ice skating, roller skating, and horseback riding, and her happiest days were often spent outdoors camping and traveling with John. She also worked for many years at Safeway in the meat department.

Mary is survived by her daughters, Patty Nelson and Barbara Pike, and her grandchildren, Sean Meehan, Neil Meehan, and Tara Barnett. She is preceded in death by her beloved husband, John O’Neill, and her grandson, Chad Meehan, with whom she is joyfully reunited.

Mary’s life was a testament to love, family, and the beauty of simple pleasures. She leaves behind memories that will be cherished by all who knew her.

A celebration of Mary’s extraordinary life will be held Thursday, October 2, 2025, at 11:00 a.m. at Olinger Crown Hill Cemetery, 7777 W 29th Ave, Wheat Ridge, CO 80033.