I have never found one of these beauties. But Chris Pechal found this blooming at The Sea Ranch recently. It's called Pleated Gentian, Gentian affinis.
I shared Chris’ photo with botanist Peter Baye. He confirmed the ID, writing, “Definitely Gentian affinis. That’s an exceptionally pure and large-spotted one. It is distributed right along the immediate coast in well-drained sandy marine terrace soils. There are some old records of it near you in Anchor Bay, and Amy Ruegg reported one from Sea Ranch.” I’ll be looking at my place in Anchor Bay. I have well-drained sandy soil!
Breezy and cooler today, temps in the low 70's.