It is found in mountainous areas of the western United States, where it grows on rotting conifer wood, often fir logs.

Fruit bodies appear similar to unopened mushrooms, measuring 1–4 centimetres (3⁄8–1+5⁄8 in) tall with 1–2.4 cm (3⁄8–1 in) diameter caps that are whitish to brownish.

A whitish, cottony partial veil is present in young specimens, but it often disappears in age and does not leave a ring on the stipe.

Harkness found the type collection growing on logs of lodgepole pine (Pinus contorta) in the Sierra Nevadas at an elevation of 7,000 feet (2,100 m).

[3] Curtis Gates Lloyd discussed the species in a 1903 publication, but named it rubigenum, stating that nubigenum was incorrect because of typographical errors carried down from Pier Andrea Saccardo.

[4] The genus Nivatogastrium was circumscribed by American mycologists Rolf Singer and Alexander H. Smith in 1959, who set N. nubigenum as the type and only species.

Its color ranges from somewhat ochre to tawny to dirty yellow to whitish (especially in age), and the surface texture is smooth to slightly fibrillose.

[2] In 1971, Egon Horak described the species Nivatogastrium baylisianum, N. lignicola, and N. sulcatum from New Zealand, all of which differ from Pholiota nubigena by microscopic characters.

[14] Thaxterogaster pingue is somewhat similar in appearance to P. nubigena, but can be distinguished from the latter by its terrestrial habitat, autumn fruiting period and lack of odor.

[2] Pholiota nubigena fruits singly, in groups, or in small clusters on rotting conifer wood, especially fir and lodgepole pine.