Pretty clearly, what the BLM expected to be here, isn't. Rather than a tidepool, this is a beach.
Chris (@allochtonous) and Anne (@highlyanne) are in town. Yesterday, we went up Marys Peak for a quick overview of big-picture Coast Range geohistory (and to escape the heat); today, we're headed down to Roseburg to see some of the stratigraphy that was emplaced before the Tyee Formation (Eocene turbidites) and after the seafloor/oceanic plateau basalts that form the basement rock of westernmost Oregon. Rocks in that interval were not deposited in this area. At any rate, I'm likely to interrupt this segment on Yaquina Head again, when I get photos transferred from my camera to my laptop.