Collection location: Wilder Ridge, Humboldt Co., California, USA [Click for map]
Overall it was very poor collecting in southern Humboldt county this year. I believe the reason was an early cold snap which shutdown most of the mycorhizal species.
Hard to tell from photo, but looking in M.D., it looks to be either C. sodanitus gp. or C. cedretorum. But the sodanitus is supposed to have purple tones in the cap no matter what, esp. on the edges, and usually the stipe is thinner. C. cedretorum looks closer, but doesn’t usually have purple gills, except for a slight tone of purple for a little while just before the brown from spore dev. But if it is cedretorum it is supposed to have purple tones in the flesh if you cut it open. Actually looking at the notes he remarks that C. montanus is similar, but with violet gills, and is common in the western mountains under old growth conifers.
But from the colors of the cap, stipe and gills, and esp. the bulbous base, this is what you get in M.D.