Environmental Description:  This alliance occurs in late-melting snowbeds from mountain ranges of in the central Rocky Mountains. Stands occur as small patches and are documented from 1930 m to over 3200 m elevation in the mountains of southwestern and northwestern Montana (Cooper et al. 1997, Reid et al. 2004). In southwestern Montana it is associated with the ranges (Anaconda-Pintlar, Madison, East Pioneer) receiving greater precipitation than other ranges of this region. In northwestern Montana and the Bitterroot Range, this association occurs within the upper subalpine zone, as well as alpine habitats. Sites often occur as small patches on depressions and protected slopes of gentle to moderate inclination on lee sides of ridges were snow accumulates in winter. This moderately deep snow layer protects the dwarf-shrub vegetation from desiccation from winter winds. The water from late-melting snowbed and subirrigation from surrounding slopes creates wet to moist soil conditions during the relatively short growing season, although not so late and short as ~Carex nigricans Wet Meadow (CEGL001816)$$. It is a moderately chionophilous type often noted as a dark green ericaceous border around long-persisting snowbed depressions. Soils are composed of varied parent materials, but are always strongly acidic, usually with substantial peat layers. In Montana, the parent materials are crystalline rocks, such as granite and quartzite. Adjacent vegetation is usually a mosaic of Abies lasiocarpa parkland on slight ridges, Carex meadow on saturated soils, and alpine fell-fields, rock, or ice on higher elevation alpine slopes.