Important Plant Areas of Montana

Geography

Montana is the largest state in the northwest portion of the United States and contains much of the northernmost portion of the Rocky Mountains. Approximately the eastern two-thirds of the state is part of the Northern Great Plains, a large area dominated by semi-arid grasslands. Montana is not particularly species-rich because a large portion was covered by ice during the last glacial epoch.

On the other hand, Montana has some of the most extensive and relatively undisturbed landscapes in the country. In addition, small parts of the state support plant communities and species that are peripheral outliers from other parts of the continent such as Arctic-Boreal, Pacific Northwest and Great Basin, that can be important for conservation.

The Montana Native Plant Society

The Montana Native Plant Society (MNPS) began the Important Plant Areas Program in 2008, modelled after the National Audubon’s Important Bird Areas Program. MNPS used the Plant Species of Concern list developed by the Montana Natural Heritage Program that ranked plants by their global and within-state rarity and degree of threats. The first IPA was dedicated in 2010. Since then eight other IPAs have been dedicated with an additional one currently being considered. Nomination guidelines are provided on the MNPS website.

IPAs

The Pryor Mountains IPA supports numerous species that are common in the arid Great Basin to the south and west. In addition, the Pryors IPA supports five species that are endemic to this area of Montana and adjacent Wyoming.

The Centennial Sandhills IPA contains a large portion of the largest sandhills habitat in the state and supports four species of rare plants that are generally found only in open sand habitats. Both of these IPAs are threatened by off-road vehicle use.

The Pine Butte Peatlands IPA is the largest fen complex in Montana. This IPA supports 13 species of boreal plants that are considered rare in the state, although all are more common to the north. Outside of warming from human-caused climate change, there are few threats because the majority of the IPA is owned and managed by The Nature Conservancy.

The Big Sheep Creek Basin IPA encompasses a very diverse landscape in the southwest portion of Montana. It supports 13 species of plants considered rare in Montana, two of which are regional endemics. Threats include mineral extraction, weed invasion, livestock grazing and water diversion.

Photography by: Peter Lesica