sixty-one bird species or approximately 70% of those found in Montana inhabit the valley.
At least 150 bird species breed in the valley. The valley has been the base for trumpeter
swan recovery efforts in the Northern Rockies since a remnant population was discovered
here in the early 1900's. The Centennial Valley hosts the densest breeding population of
peregrine falcons, ferruginous hawks, and trumpeter swans in Montana. The valley
historically had a large population of sage grouse and still maintains remnant
populations. Red Rock Creek and Upper Red Rock Lake contain one of the only native
lacustrine populations of Arctic grayling in the lower 48 states. Several streams in the
valley contain genetically pure westslope cutthroat trout. The stream habitat of the
valley also provides habitat for river otters. Lying only 20 miles from Yellowstone
National Park, the Centennial Valley is a linkage zone and provides secure habitat for
wide ranging native predators such as grizzly bear, wolf, wolverine, and lynx.
Valleys soils give rise to a diverse array of plants and plant communities,
including some of considerable scientific importance. Location records indicate 41 plant
Species of Special Concern, including five that may be globally rare and seven that are
known only from the Centennial Valley in Montana. Vegetation in the Centennial Sandhills
represents one of Montanas most intact native plant associations and includes at
least five state-rare species.