Alta Rockefeller Prentice was the third daughter of oil tycoon John D. Rockefeller (1839–1937) and his wife Laura Celestia "Cettie" Spelman (1839–1915). Alta married Colonel Ezra Parmalee Prentice (July 29, 1863–1955), a prominent Chicago attorney, son of Sartell Prentice and wife Jemima Parmalee, in 1901. Alta and Ezra had three children: John Rockefeller Prentice (1902–1972), Mary Adeline Prentice Gilbert (born 1908), and Spelman Prentice (1911–2000). She founded Alta House (c. 1900), a settlement house in Little Italy in Cleveland, Ohio, which is named in her honor. In 1910, Alta and Ezra bought 1,400 acres (5.7 km²) of land near Williamstown, Massachusetts. Elm Tree House, the Prentices' 72-room summer home on Mount Hope Farm, was completed in 1928. In the 1930s and 1940s, several geneticists were employed by Ezra to develop more profitable farm animals, particularly cattle and poultry. At that time, Mount Hope Farm was one of the most outstanding experimental farms in the United States. The Manager of Mount Hope Poultry Hatchery was Olin Dana Graves. Alta died in 1962. Her property was willed to New York's Lenox Hill Hospital. Shortly thereafter, Elm Tree House was purchased by its current owner, Williams College.

(Note: Daughter's name: Madeline Prentice Gilbert born on 29th November, 1907.)

From Time Magazine, June 29, 1962:
Died. Alta Rockefeller Prentice, 91, last surviving of John D. Rockefeller's five children, and Governor Nelson Rockefeller's aunt, who, in the family tradition of philanthropy, shared her wealth with settlement houses, hospitals and museums; after a long illness; in Manhattan.
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Individual: Alta Rockefeller Prentice
Estate Value: $ 12,775,531
Value after Probate: $ 4,103,216
Probate Cost: $ 8,672,315
Probate Cost % of Estate Value: 67.88%