Daniel N. Clark was born on May 24, 1943 in Walla Walla, Washington, the son of Reed Lafayette Clark Sr. and Estelle Johnson Clark. He attended Walla Walla Public Schools and then Whitman College, graduating in 1965 with a B.A. in Political Science. After graduation he attended the School of Law at the University of California at Berkeley, graduating with a J.D. in 1968.

Barbara Hershey Clark was born in Los Angeles, California on October 30, 1942. Raised in Los Angeles, she attended Reed College in Portland, Oregon and graduated with a B.A. in Political Science, and then attended the School of Law at the University of California at Berkeley, where she and Daniel Clark met.

The two married on June 16, 1968 and both practiced law in the Bay Area until 1971, when they moved to Walla Walla. The couple has two children, Rebecca and Jeremy.

On moving to Walla Walla, Daniel became a partner in the law firm of Ringhoffer and Clark before eventually establishing his own firm, and has also been involved in a variety of local and international organizations, including Peace Brigades International, the Bridge Rehabilitation Project, Walla Walla Mental Health Center, the Walla Walla County Bar Association Legal Aid Office, Walla Walla County Legal Defense Association, and the Frenchtown Historical Foundation, among many others.

Barbara Clark has worked in administrative law in Walla Walla, as well as directing the Neutral Ground Dispute Resolution Center. She was also the founder of Walla Walla 2020 and served twenty-two years on the Walla Walla City Council, holding two terms as mayor. Both she and Daniel have also published several books over the course of their lives, including "Becoming an Environmentalist: How I Learned to Stop Worrying and Love the Energy Crisis" (1976) and "A Privileged Life: Memoirs of an Activist" (2013).