A set of around 10 shallow digs 3-5 cm deep tipped me off. Raking back the layer of Redwood needles another 2-5 cm (total depth probably something like 4-8 cm) turned up a single fruitbody situated amongst a lot of branched white rhizomorphs (see photos). Soil and humus had a strong vegetal odor – not great but not particularly unpleasant.
Peridium blushed rosy and royal purple!
Cross-sectioned fruitbody shows many olive-colored locules (likely paler because the fruitbody is small and immature).

Apparently has not been recorded in Santa Cruz County since the 80s, and only found a few times anywhere in recent decades.