Mason, who worked as a librarian at the university from 1957 until her retirement in 1999 and was Spencer's first librarian, died in 2011. To be administered by the KU Endowment, the estate gift will establish the Ann Hyde Fellowship for Medieval and Early Modern British and European Manuscripts, in honor of Mason's lifetime friend, Ann Hyde, who died in June 2014. Hyde served as manuscripts librarian at the research library until she retired in 2000.
During her career, Mason built special collections of research materials, guided generations of scholars and librarians, and was a leader in the Rare Books and Manuscripts section of the American Library Association. She received numerous professional awards, including the first Chancellor's Award for Distinguished Librarianship in recognition of her contributions to KU Libraries and her international leadership in rare book and special collections librarianship. In 1980, she was named to the KU Women’s Hall of Fame. Before her retirement, an anonymous alumni couple established a scholarship fund named for her and Joseph Rubenstein — the library’s head of Special Collections from 1953 to 1963 — to provide support for KU students who intend to pursue a career in an academic or research library.
"Sandy was a pioneering scholar-librarian," said Beth Whittaker, KU Libraries assistant dean for distinguished collections, director of the Spencer Research Library, and a former student assistant of Mason's. "She played a significant role in building the renowned and rich collections within this library, and she encouraged me to become a librarian. It is an honor to accept this truly transformational gift."