Hygrophorus hypothejus

This is a key to gilled mushrooms, that is, mushrooms having a definite cap with a fertile surface consisting of gills. The fruiting body usually also has a stem, although that may be lateral or absent (usually, then, the mushroom is growing from wood). You can use this key to identify mushrooms that you find.

Fruiting body containing fibers (usually in the stalk)

Spore print "light-colored": white or buff, sometimes tinged with pink or tan. Greenish and (except for the Russulales) yellow spore prints also go here
Stalk fibrous, not fracturing like a piece of chalk

Gills (at least) with a distinct waxy or silky feel, due to unusually long basidia
No annulus, armilla or volva
Cap often slimy
They tend to grow in cold areas, and sometimes fruit at times when it's too cold for other mushrooms
Several have an insulating slimy universal veil. This veil leaves the cap and the stalk slimy, except for the upper stalk where the gills covered it when the mushroom was a button.

Cap usually larger than 2" across; often viscid or slimy; usually white or dull colored
Stature usually robust
Stalk fleshy; only rarely hollow

Colorful Hygrophorus     Section Cap colored white, greyish purple, pinkish, or just including some other coloration other than those listed for Dull Hygrophorus

Links from Look-alikes Dull Hygrophorus     Section Cap some shade of grey, brown, greyish brown, or brownish grey

Hygrophorus hypothejus     (Fries) Fries