Mycena overholtsii, commonly known as the snowbank fairy helmet or fuzzy foot, is a species of fungus in the family Mycenaceae.

Formerly known only from high-elevation areas of western North America, particularly the Rocky Mountain and Cascade regions, it was reported for the first time in Japan in 2010.

The species was first described by mycologists Alexander H. Smith and Wilhelm Solheim in 1953, on the basis of specimens collected in the Medicine Bow Mountains of Albany County, Wyoming.

[2] It is commonly known as the "snowbank fairy helmet",[3] or "fuzzy foot",[4] although it shares the latter name with Tapinella atrotomentosa[5] and Xeromphalina campanella.

[8] They have caps that are 1.5 to 5 cm (1⁄2 to 2 in) in diameter, and convex in shape, developing an umbo (a central protrusion resembling a nipple) in maturity.

[9] The caps are somewhat hygrophanous, and depending on age and state of hydration, range in color from brown or grayish-brown,[10] to dark or bluish-gray.

[2] The gills have an adnate, adnexed, or shallowly decurrent attachment to the stem, and are initially closely spaced before becoming well-spaced at maturity.

The cheilocystidia (cystidia on the gill edge), which are scattered and interspersed with basidia, are roughly cylindric to fusoid (spindle-shaped), smooth, hyaline (translucent), and measure 45–65 by 2–5.5 μm.

[14] Another similar species is M. semivestipes,[15] which can be distinguished by its bleach-like odor, an eastern North American distribution, fruiting season during summer and autumn, and small spores measuring 4–5 by 2.5–3 μm.

[12] Cool nighttime temperatures reduce the snowmelt rate, and help ensure that spores released by the mushroom will be dispersed into the soil.