Cap 5.0-14.0 cm broad, convex, nearly plane in age, sometimes centrally depressed; margin at first incurved, decurved to occasionally upturned in age; surface sticky when moist, otherwise dry, glabrous, white to cream; context white, firm, unchanging, thin at the margin, up to 3.0 cm at the disc; odor and taste mild.
Gill adnate to decurrent, close in youth, subdistant in age, white, becoming cream-colored; lamellulae not common, up to 3-seried.
Stipe 4.0-6.0 cm long, 2.0-4.0 cm thick, short, stout, solid, the base usually enlarged to bulbous; surface glabrous, silky-shiny, colored like the cap; context white, firm, fleshy, unchanging when cut; partial veil fibrillose-membranous, evanescent, leaving remnants on the bulbous base, occasionally near the apex, or on the partially expanded cap.
8.0-9.5 x 4.5-5.5 µm, elliptical, smooth, thin-walled, inamyloid; spore print white.
Solitary to scattered under conifers in the Sierra and higher elevations of the Coast Range; fruiting in the spring near melting snow.
Edible, generally considered mediocre.
Hygrophorus subalpinus is a conspicuous member of the Sierra snowbank mycota. Large size, compact stature, white color, decurrent waxy gills and fibrillose veil, sets it apart from all but a few montane fungi. Compare with Lenzites montanum, a later-fruiting, lignicolous species, with a pale cap and serrated gills, and Tricholoma vernaticum (synonym: Armillaria olida), which fruits simultaneously with Hygrophorus subalpinus, but is greyish, less robust, and has a distinct raw potato odor. Other spring-fruiting Hygrophorus species like H. purpurascens, H. marzuolus, H. camarophyllus and H. goetzii can be distinguished by color, size, and stature. Occasional fall fruitings of Hygrophorus subalpinus can be confused with Russula brevipes and Tricholoma magnivelare. Russula brevipes is differentiated by a brittle texture (a stipe that breaks cleanly), absence of a veil, and amyloid ornamented spores, while Tricholoma magnivelare, (Matsutake) has a distinctive spicey odor and tends to develop rusty-brown stains.