Comment: the spores for this species should be 4-8 X 2-4 microns. I measured these to be approx. 5.5-6.1 X 3.3-3.9 microns.
I can’t say for sure what old log they were growing on, but the area is heavy in Douglas fir, tanoak as well as redwood. Also according to Arora, in our area it favors Douglas fir and pine.