Zilpha Keatley Snyder

Zilpha Keatley Snyder (May 11, 1927 – October 8, 2014) was an American author of books for children and young adults. Three of Snyder's works were named Newbery Honor books: "The Egypt Game", "The Headless Cupid" and "The Witches of Worm". She was most famous for writing adventure stories and fantasies.
Biography.
Snyder was born in Lemoore, California, and spent all but brief periods of her life in Northern California. She began writing fiction in the 1960s and worked with editor Jean Karl on her debut novel "Season of Ponies", which Atheneum Books published in 1964.
Snyder was heavily involved in "Below the Root", a 1984 computer game that is set in the Green Sky universe after the events of "Until the Celebration". She worked with programmer Dale Disharoon on several aspects of the game including the map and characters.
Between 1964 and 2011, Snyder completed 46 books. Atheneum published her first 22 books and (as a Simon & Schuster imprint) her last three books.
Snyder died at the age of 87 in 2014 from a stroke in San Francisco.
Awards and Honors.
In 1998, Snyder was awarded an honorary Doctor of Humane Letters (L.H.D.) degree from Whittier College.