View the spoiler for my guess at what I think it might be, but please first come to your own conclusion before looking at mine β I don't want to bias your guess.
My guess
Psilocybe cyanescens
They were found in mid-november in the Salish Coast region of Cascadia. They were growing out of woodchips composed of a mixture of western hemlock (majority), and western red cedar.
Side view of one full mature specimen:
A group with a sample of the substrate (the cap appears to be umbonate):
A closeup side view, and internal view of the stem (it appears to be hollow):
Cross section of the gills β they appear to be adnate, or sub-decurrent:
Underside of view of the gills:
Spore print (first on white background (the split is due to two halves), second on a black background):
Examples specimens once dried:
Examples of the colony, and the location/substrate in which it was growing:
Cross-posts:
I figured that it'd be worth it to include it, at least for documentation purposes, if not for the potentially unlikely case that it does aid identification in some meaningful way.