These plants were growing near the trail at the base of Pilot Rock, in 'serpentine-like' substrate (though not actually serpentine, but rather derived from Tertiary mafic basalt flows, dikes, and/or plugs...cf. here). Pilot Rock is a prominent volcanic plug not far from I-5 and the California border.

Since I was just over the border from California, I consulted the Jepson eFlora Key to Polemoniaceae which led to unambiguously to Collomia tracyi. I was somewhat surprised to find that, at the time of posting here, the Oregon Flora Project checklist for Polemoniaceae does not include this species under Collomia, though I'm quite confident of the ID here. Indeed, this alternate Oregon checklist of Polemoniaceae does list C. tracyi, and refers to voucher not far from Pilot Rock. I cross referenced by keying in Abrams's ''Illustrated Flora of the Pacific States'', which also led to C. tracyi. Here is a link to Mason's original 1948 description of Collomia tracyi.