I have to laugh at this one!! I grew up partially at Vandenberg AFB, CA, and tri-tip was king.
Never heard of it again until, 30+ years later, husband and I were camping out and visiting our old haunts. When we hit that area, I kept hearing about "Santa Maria Barbecue". Huh? What in the #$%^&* is that? So I asked a local friend and she said "grilled tri-tips and pinquinto beans". Oh, you mean what we ate at least once a month? Yes (You have to know, in my childhood, barbecue meant what the foodies here now call grilled).
It consisted of marinated tri-tips, and pinquito beans (as it sounds, pinquintos are a small version of pintos) done in a chili type preparation (our local friends called them "chili beans").
My husband thoroughly enjoyed this experience, which we had about a dozen times as we traveled the are.
Best is Pozo, California.