SF and LA are pretty much at opposite ends of California.

The California-Oregon Border hits the coast at the 42 parallel, and the California Mexico Border starts at 32.5. SF's latitude is 37.8, making it only 55% of the way up the coast. Far from being on opposite sides of California, San Francisco is only a bit past the midpoint. The misconception that SF is at the opposite end of California is likely due to the fact that past San Francisco, Northern California is pretty sparcely populated (an Oregonian friend of mine once describe Northern California past the Bay as "not inhabited by humans").