Funny, enough - this is similar to a wall I strolled underneath out at starvation creek this past weekend. Taking the Starvation Ridge trail instead of Defiance, i snuck a peek along the base. A big mess of moss, choss and a few animal bones. But underneath the roofs, the basalt columns somewhat unbroken.
Then I found bolts heading up a slab. I saw two and didn't follow in the pouring rain, but someone had billcoe's idea: clean it and see what pops out. There was certainly enough "prior wall" along the base. Pulling that stuff could send junk all the way to the 84 with an unlucky roll, so I imagine someone realized this and gave up. You'd have to pull an awful lot of rock to find smiles, but then again, there was maybe a 1/4 mile of wall to check out.
I would name it the Jenga Wall if given a vote. [pull pieces without with having it crash down - heh]
I've typed a few searches here and elsewhere without much. I'm not "starving" for adventure that much. But if someone is, chew on that.
EDIT: picture attachment