Rosemarie Sanguinetti Gwynn is a member of a well-known and active Yuma pioneer family.   The first step toward what is now the Century House Museum came when the Sanguinettis opened part of their property to the Yuma Art Center for classes in 1959.   In 1972, Mrs. Gwynn and her brother donated the Century House, gardens and Adobe Annex to the Arizona Historical Society for continued use as a Museum facility.  This became the first branch museum of the Arizona Historical Society, Rio Colorado Chapter.

Her interest in history and in preservation of the history and culture of the Yuma area led Mrs. Gwynn into a variety of roles, including the writing and publishing of a book titled Early Yuma.  Active in spearheading and operating the Century House Museum,she has also served on the boards of the Yuma City-County Library, Arizona Historical Society, Rio Colorado Chapter of the Arizona Historical Society, and was the first president of the Yuma County Historical Society.  She also helped to bring Los Posados back to Yuma.   This traditional Mexican Christmas procession, long missing from the Yuma Cultural scene, was received with much success.

Mrs. Gwynn was named Yuma's "Woman of the Year" in 1965 and received the Arizona Historical Society's Bent Spittoon Award in 1986, which honors those who give their time and efforts on behalf of the Society.

Rosemarie Sanguinetti Gwynn represents the spirit in which the Sharlot Hall Award is presented.  Her diligent work has certainly contributed enormously to the understanding and awareness of Arizona and its history.