Contra Costa County is located in northern California. It is bounded on the south and west by Alameda County; on the northwest San Francisco Bay (San Francisco and Marin Counties); on the North by San Pablo Bay, the Carquinez Strait, and Suisun Bay (Solano and Sacramento Counties); and on the east by the San Joaquin River (San Joaquin County).
Mount Diablo can be seen from most of northern California cities. It is an isolated peak of 3,864 feet (1,178 m), and it appears from many angles to be a double pyramids that include many subsidiary peaks. The peak is the centerpeice of Mount Diablo State Park, a park of about 20,000 acres.
Rice taught in nearby Oakland and made frequent painting trips throughout the county.