You may want to look at some of the back-and-forth between the coast and the mountains...

For instance, you may want to continue down the coast into the Redwood Parks in northern CA, then backtrack up to Crater Lake (and Oregon Caves).

From there, you could shoot down to Lassen, and continue down the interior to Yosemite/Sequoia/Kings Canyon, before returning to the coast in SF.

From there, continue down the coast to SD.

You'd miss the northern CA coast, but you cut out some of the back-and-forth/backtracking.