Ok, this is the 3rd time I've seen this. I'm convinced it's not B. edulis, so time to make a concerted ID effort. No staining reaction, smell pleasant, somewhat porcini-like. Cap viscid when wet but I don't recall it being that slimy on previous, drier encounters. Seemed to be growing under huckleberry, but there was a pine some distance up the hill, and some nearby bays and possibly chinquapin and maybe some kind of alder. I didn't notice any particularly large oaks nearby. Observed in Huckleberry Botanic Preserve, Oakland, CA, USA. Cap about 5 cm in diameter.