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The Centennial Valley

Centennial Valley wetlands
Centennial Valley wetlands
© Jim Steinberg

Why the Conservancy Selected This Site
Conservation biologist Reed Noss in a 1991 biological assessment of the Greater Yellowstone Ecosystem ranked the Centennial Valley as the highest conservation priority in the study area. Located 20 miles from Yellowstone Park's western border, the Centennial provides a critical corridor for grizzlies and other wildlife that travel from Yellowstone to the northern Rockies. The valley's expansive wetlands are home to hundreds of bird species, and Red Rock River and its tributaries contain native populations of rare Arctic grayling.

The Centennial retains the same ranching and wide open, wildlife-rich character as it did a century ago. It's a quiet treasure of vast grasslands and wetlands ringed by the magestic Centennial Mountains to the south and the Gravelly Mountains to the north.

Threats
Inappropriate development and poor land-use practices have the potential to compromise the integrity of the Centennial's ecosystem. Much of the agricultural countryside of southwest Montana is undergoing transformation to resort and residential development. The combination of demand for rural, scenic western properties and uncertain agricultural economics makes rural land vulnerable to sale and subdivision. 

Non-native plant species offer another stress on the terrestrial ecology of the Centennial. With the easy transfer of weed seeds from vehicles, and limited government and private resources for weed management, weed infestations in the Centennial are of serious concern.

Plants
Forty-one plants found in this valley are listed by the Montana Natural Heritage Program as species of special concern. Five of these rare plant species are found in the unique sandhills found in only one other location in Montana. The spectacular peaks of the Centennial Range are cloaked by dense coniferous forest with some of the oldest trees in southwestern Montana.

Animals
Upper and Lower Red Rock Lakes on the 45,000-acre Red Rock Lake Wildlife Refuge give life to 241 species of birds. The valley contains the highest nest density in the West for trumpeter swans, and lies along one of only two primary swan migration corridors. The Centennial also hosts the densest population of peregrine falcons and ferruginous hawks in Montana, and a healthy population of bald eagles and osprey.

One of Montana's two remaining native populations of Arctic grayling as well as pure-strain westslope cutthroat trout inhabit the valley's river system.

The Centennials and the nearby Madison, Gravelly and Henry's Lake ranges provide habitat for native predators such as the grizzly bear, wolf, wolverine and lynx. Moose are abundant year-round. Pronghorn and elk undertake seasonal migrations extending tens of miles through the valley and along its foothills between their summer and winter ranges.

Our Conservation Strategy
Almost 100,000 acres here are in large ranches, 90 percent of which are stewarded by 15 families. These multi-generation ranching families have in common a desire to preserve their ranching operations over time and protect habitat for the Centennial Valley's wildlife. Most of the valley's ranchers have shown a commitment to working with the Conservancy along with federal agencies. Conservation easements, both paid and donated, are a key tool for protecting these ranches into the future. The Conservancy is also working with landowners and other partners on weed control and habitat restoration projects.

What the Conservancy Has Done/Is Doing
Since the Conservancy began its work in the Centennial, it has helped institute a massive weed management program that has resulted in the largest weed district in the state. Working hand in hand with landowners has helped the Conservancy gain local credibility. Now, the Conservancy, the Fish and Wildlife Service and other partners have used conservation easements and land adcquisition to protect around 43,000 acres of private land in the valley. (See Dulany, Hess, Huntsman)