Which geological feature separates Southern and Northern California?

The Tehachapi Mountains serve as the geographical divide between Southern and Northern California. This mountain range runs east to west, and its position has played a crucial role in the state's geography and climate. It effectively acts as a barrier, influencing weather patterns and ecosystems on either side.

The Sierra Nevada Mountains, while significant, run north to south along the eastern edge of the state and do not separate Northern and Southern California in the same way. The Cascade Range is primarily associated with northern California and the Pacific Northwest, and the San Andreas Fault is a major geological fault but does not function as a distinct separator between the two regions of the state. Thus, the Tehachapi Mountains are correctly identified as the main feature that delineates the dividing line between Southern and Northern California.