Witkin then moved from pupil to teacher, teaching at Saint Martin's for two years. He then moved to the United States. At Bennington College, Bennington, Vermont, Witkin worked with a community of artists known as "the Green Mountain boys" who either taught at the school or were part of the local arts community, including notables such as painter Kenneth Noland, Helen Frankenthaler, Larry Poons, Paul Feeley and Jules Olitski and art critic Clement Greenberg.
During this time Witkin developed the style which would form the remainder of his works. Here he discovered a process of pouring molten bronze into wet sand on the ground to create organic appearing forms. By assembling these forms he engaged in "...creating language out of the behavioral flow of metal, wresting order from chaos" as he is quoted as describing the process in his obituary at The Times Online website. The remainder of his works were primarily in bronze, both poured and then cast, colored by chemicals to have a variety of patinas. However, some later work was also done in stone, though in the same style as the poured bronzes.Wikipedia