As a leader of the Zen Center of Spokane and the Three Treasures Sangha of the Pacific Northwest, Duffy first began practice with Aitken-roshi in 1981 and received permission to teach from him in 1992. Five years later, he was given the title Roshi and underwent Dharma transmission. Duffy has also studied with other masters, including Thich Nhat Hanh and Joan Riek. He brings his roles of spouse, father, and psychotherapist, as well as years of endangered species work and wilderness wanderings, to his teaching.