Ms. Fork, 85, died peacefully at home March 17 while surrounded by her family.
Born in New Jersey, she moved West after some college in Vermont. She acquired a bachelor's degree in zoology from the University of Colorado, then did graduate work in molecular biology at the University of California at Berkeley, where she met David Fork. They married in 1958.
The couple moved to La Jolla, where Mr. Fork was employed at the Scripps Institution of Oceanography, and Ms. Fork at the Scripps Clinic and Research Foundation. They later moved to Europe, where Mr. Fork worked as a post-doctoral fellow.
In 1963, they moved to Portola Valley, and in 1974, to Woodside, where they lived for 40 years. They raised three daughters.
Ms. Fork was an enthusiastic skier, rock climber, mountaineer, backpacker and hiker and founded the Wednesday Walkers, a group that met for hikes in Woodside and Portola Valley. She liked to explore canyons and climb rocks in Yosemite National Park and in the southern Sierra Nevada.
"She will be remembered with great affection for her caring nature, her quiet courage, her dry sense of humor, and her love of adventure," the family said.
Ms. Fork is survived by her husband; her daughters, Laurie Peterson, Patricia Orlando and Susanne Fork; and five grandchildren.
The family prefers donations to the American Parkinson Disease Association (www.apdaparkinson.org) or the Michael J. Fox Foundation for Parkinson's Research (www.michaeljfox.org).
Obituaries are based on information provided by the family.