From San Luis Obispo, go north on the 101 to the 46 west. Watch for a street on the left called old creek rd... take it! The road is narrow, and the turns are tight. Once you get to the top, You'll be rewarded with an awesome view of a lake to your right, while overlooking the ocean below....Continue down into Morrow Bay, and make a left on Coast Highway, and that'll lead you right back to the 101 freeway.
**note: There are two Old Creek Roads, Turn left on the second one you see...the first dead ends.