Collagist, assemblage artist, sculptor, and painter Robert Keith Gronendyke was born on May 15, 1930 in Muncie, Indiana. His formal education began at Compton Junior College in California, where he earned his AA in 1950 before enlisting in the U.S. Marine Corps, serving for two years. He then continued his art education, receiving his BA and MA at California State College, Long Beach, in 1955 and 1960, respectively. He exhibited in numerous solo and group shows throughout the U.S. and overseas, including at the Crocker Art Museum (1983) and in the San Francisco Art Institute's "The Art of Assemblage" (1962) and the "Delgado" (1964) exhibitions with Bruce Conner, Roy De Forest, Charles Gill, Tony DeLap, and others.

In addition to his personal artistic output, he taught art in the U.S. and abroad, including Palo Alto and Santa Maria public high schools of California; Eastern Montana College, Billings, MT; Jamia College, Karachi, Pakistan (Fullbright-Hayes Instructor of Art); American University, Beirut, Lebanon; and Sonoma State University, Rhonert Park, CA. He died in Yountville, California, on March 7, 2022.