Rothko, during the mid-1940s, was in the middle of a crucial period of transition, and he had been impressed by Clyfford Still's abstract fields of color, which were influenced in part by the landscapes of Still's native North Dakota. In 1947, during a subsequent semester teaching at the California School of Fine Art (known today as the San Francisco Art Institute), Rothko and Still flirted with the idea of founding their own curriculum or school. Still was considered one of the foremost Color Field painters – his non-figurative paintings are largely concerned with the juxtaposition of different colors and surfaces. His jagged flashes of color give the impression that one layer of color has been "torn" off the painting, revealing the colors underneath, reminiscent of stalactites and primordial caverns. Still's arrangements are irregular, jagged, and pitted with heavy texture and sharp surface contrast as seen above in "1957D1".