These plants were growing south of the parking lot for Pilot Rock trailhead, in the open 'serpentine-like' substrate area (actually not serpentine, but derived from Tertiary mafic basalt flows, dikes, or plugs...cf. here). Pilot Rock is a prominent volcanic plug not far from I-5 and the California border.

Although I keyed these in the field using JEPS93, arriving at Sedum stenopetalum, as is my habit, I keyed them again from my photos before posting. It was Oregon, just over the border from California, so I consulted the Jepson eFlora Key to Sedum which led to unambiguously to S. stenopetalum. The current Oregon Flora Project checklist for Crassulaceae includes this species, which was the best match among other species on that list that I checked out images of on the web.

Since the plant wasn't actually in California, I cross referenced by keying in Abrams's ''Illustrated Flora of the Pacific States', as well as the FNA key to Sedum...both of which led to S. stenopetalum. The plants here agree well with the (earlier phenology) images of S. stenopetalum ssp. stenopetalum from the Oregon Flora Project.