...is rimrock that I suspect is Steens Mountain Basalt (SMB), though I'm not positive about that. When I was an undergrad, the SMB was treated as its own rock unit, though compositionally and chronologically, it was clearly similar to, and possibly related to, the Columbia River Basalts (CRB). Sometime over the last 25 years or so, SMB has been regrouped as a part of CRB, so technically (and again, with some uncertainty), this is CRB.
This location is driving me nuts... I know it's between Lakeview and Adel, and everything about the FlashEarth location I've been denoting looks right... except for the gosh-darned power line. There is another spot back near the Plush cut-off that has a power line paralleling the road like this, but the road isn't the right configuration there, and it doesn't look as if there's any tuff exposed in that cut. Oh well, I'll keep looking. Until I'm happy with it, no more location links for the time being.