Illahee State Park lies on a high forested hill and the road down to the beach switchbacks down the steep slope to a parking lot built on fill and protected by a large timber bulkhead.
South of the park, the high unstable bluff reaches directly to the beach and is littered with enormous wood stumps and logs, probably an indication of what many of these shorelines originally looked like.
To the north, the shoreline is lower for the half mile north towards the mouth of Illahee Creek. This low bench is still backed by a high bluff and its origin isn't entirely clear to me. Certainly the spit at the creek mouth is depositional and it's reasonable to assume that there was fill placed to facilitate the residential (or previous) development of this area, but I wonder if there might also be a terrace of some sort. This site is on strike with the Seattle Fault and an uplifted beach might not be surprising.