“Oakland Hills” is most commonly an informal name for that section of the Berkeley Hills range which extends along the eastern side of Oakland, California. In recent decades, it has become the more common popular term although it remains “officially” incorrect among geographers and gazetteers. Before the establishment of the University of California in Berkeley, the range was called the Contra Costa Hills.
To add confusion, the common usage often also includes another officially unnamed ridge which runs in front (west) of the Berkeley/”Oakland” Hills, as well as the linear valley enclosed between the two ridges in the Montclair District along State Route 13. This other ridge, a shutter ridge created by the Hayward Fault, lends its informal name, “Rockridge“, only to the district of Oakland at its northwest end, although it extends southeast to the junction of Highway 13 and I-580 in East Oakland and includes most of the small residential community of Piedmont, California.