Clark was a member of the National Institute of Arts and Letters and the National Sculpture Society. He begun work as a sculptor in 1917 in New York City working in stone and terra cotta while teaching at the Beaux-Arts Institute of Design. After his exposure to Oriental techniques, he did woodcarving in that manner.
He was also a member of the Fogg Museum expedition to explore cave chapels near Turkestan. From this adventure, he did 20 drawings in color. In 1930, he moved to Santa Fe, New Mexico and there did sculpting of Indian heads whose titles include "Maria of Chichiti" and "Klah-Navaho Medicine Man".