The Transverse Range province of southern California is an elongate geomorphic and structural unit that trends essentially east-west across parts of Santa Barbara, Ventura, Los Angeles, San Bernardino, and Riverside Counties (pl. 4). Its name reflects its transverse orientation with respect to the adjacent provinces, especially the Coast Ranges and Sierra Nevada to the north and the Peninsular Ranges to the south. This distinctive province is geologically very complex, and comprises chains of mountains and hills that are flanked or separated by narrow to moderately broad valleys.
These features, as well as most of their structural elements, lie athwart the general northwest-southeast grain of southern California, and several of them are responsible for the anomalous east-west alignment of the coast from Point Conception to the Santa Barbara area, and along the north side of Santa Monica Bay
