This year they are "capping" the jetty at the entrance to Tillamook Bay. Huge boulders are being trucked in from a quarry outside of Seattle for the project.
The old jetty was built in the early 1900's and in this photo you can see the dark stones used to build it. My guess is it was a pretty slow process involving horses, men and a lot of shear willpower.
The light boulders to the right have been brought in to cap the jetty and sit in this staging area awaiting huge yellow frontloaders to move them out to the cranes for placement.
To get an idea of the scale, you can see Bob standing on top of the jetty past the "Danger, No Trespassing" sign (he is never one to follow the rules).