The Spokesman-Review said Cowles died late Saturday from pancreatic cancer.
Cowles, born in Elizabeth, N.J., graduated from Wellesley College and received a master's degree in history from Radcliffe College.
She married Cowles, whose family owned The Spokesman-Review newspaper and had many other business interests in the Spokane region. William Cowles was president and publisher of The Spokesman-Review when he died in April 1992 at the age of 60.
She served on the Washington State Council for Postsecondary Education for 12 years and was a member of the Governor's Temporary Committee on Educational Policies, Structure and Management. She was also a trustee of Whitman College and Wellesley College.