Born Mary Beth Harmeyer in Joppa, she was a 1955 graduate of Bel Air High School, where she was a four-sport athlete. She received an associate's degree from Towson University and a bachelor of science in general studies and a master's degree in library science from the University of Maryland, College Park.
About 1960, she was recruited by librarian Roenna Fahrney, who ran the Harford County system, to join her staff as a reference librarian. She later went into library technology and oversaw its technical services division. She and her staff processed new books and labeled them and administered catalogs.
"Mary was instrumental in introducing our computer system," said a retired colleague, Jean Armendt of Bel Air. "She did it in such a professional way. She also trained our staff to use the computer, and that staff was not always willing to accept the changes it brought. But she made it all succeed, and she helped move Harford County forward. She was a giving, good-hearted person."
In 1998, Mrs. Crisco retired from the Harford County Public Library after 38 years of service.
"I think after she retired, she became even more active in the library and community," said Terri Schell, the library's human resources administrator.
Mrs. Crisco became a member of the Harford County Historical Society and worked to list people buried in graves throughout the county. She was also interested in her family's genealogy.
"She was very supportive of the society," said Maryanna Skowronski, its director. "She was a no-nonsense person, but I felt she had a sentimental side. We have a beautiful collection of wedding dresses, and she donated hers, along with pictures and the wedding cake topper. She was a beautiful woman, tall and statuesque."
She was a Harford County master gardener and kept a rose garden at her home. She propagated cuttings of her rose bushes. She was also an accomplished cook and baker and often took sweet treats to elderly and shut-in members of her church congregation.
"She had three sons, and we all ate well," said her son, Carl Richard Crisco of Pylesville.
Mrs. Crisco made live, dried and artificial flower arrangements and worked in string art. She made intricate pictures using threads. She read novels and magazine articles and collected recipes.
She was a charter member of the Bethel 35 International Order of Jobs Daughters.
In retirement, she took tours of the U.S. with a cousin, Pauline Bell.
A lifelong member of the Mountain Christian Church, she was also a volunteer librarian. Mrs. Crisco also belonged to the Maryland Library Association.
Services will be at 11 a.m. Saturday at McComas Funeral Home, 500 W. Broadway in Bel Air.
In addition to her son, survivors include two other sons, Mark Allen Crisco of Bel Air and John David Crisco of Ellicott City; a sister, Brooke Wilson of Fredericksburg, Va.; a brother, Grayson Russell Harmeyer of West Palm Beach, Fla.; six grandchildren; and a great-granddaughter. Her husband of 36 years, Carl Crisco Jr., an Aberdeen Proving Ground employee, died in 1993.