Grasslands of the North Fork Valley, Glacier National Park, Montana

A series of 40 grassland communities occurring in the North Fork Valley in Glacier National Park was subjected to detailed phytosociological investigation. These grasslands are somewhat phytogeographically isolated from other northern Rocky Mountain grasslands in Washington, Idaho, and Montana in the United States, and from the Alberta fescue grasslands in Canada. Compositionally, the North Fork grasslands display features characteristic of grassland vegetation on both the west and east sides of the Continental Divide. The four major grass species achieving dominance in the North Fork Valley are Agropyron spicatum, Festuca idahoensis, Festuca scabrella, and Danthonia intermedia. Environmental factors possibly important in the distribution, composition, and maintenance of these grasslands are discussed.