Mycena overholtsii, commonly known as the snowbank fairy helmet or fuzzy foot, is a species of fungus in the family Mycenaceae. The mushrooms produced by the fungus are relatively large for the genus Mycena, with convex grayish caps up to 5 cm (2.0 in) in diameter and stems up to 15 cm (5.9 in) long. The gills on the underside of the cap are whitish to pale gray, and initially closely spaced before becoming well-spaced at maturity after the cap enlarges. The mushrooms are characterized by the dense covering of white "hairs" on the base of the stem. M. overholtsii is an example of a snowbank fungus, growing on well-decayed conifer logs near snowbanks, during or just after snowmelt. Formerly known only from high-elevation areas of western North America, particularly the Rocky Mountain and Ca