Described by the naturalist John Muir in 1894 as "the mountain stream's own darling" and "the hummingbird of blooming waters," the American dipper is widely known for its characteristic dipping behavior, as well as its amazing ability to live and feed in the rapids and cascades of cool streams in the mountains of western North America. The Black Hills of South Dakota is the easternmost mountain range inhabited by the American dipper. The Black Hills dipper (Cinclus mexicanus unicolor) is also of particular importance because it is isolated from populations in other mountain ranges by 200 miles of grasslands.

Despite its ecological value, the Black Hills dipper has been declining and is now in danger of extinction. Today, only Spearfish Creek in the northern Black Hills supports a healthy population of dipper. Even French Creek and Rapid Creek, which once supported thriving populations, have not supported breeding populations for years. In 1996, the dipper was listed as a Threatened Species by the State of South Dakota.

Water pollution and stream habitat degradation appear to be the major causes of the dipper's decline in the Black Hills. The dipper is extremely sensitive to stream pollution and is an important indicator of water quality. Known causes of pollution include livestock grazing in streams and riparian areas, logging, roads and road construction, and mining waste. Douglas Blacklund, a Black Hills dipper biologist, observed that, "A major fire in the Spearfish Canyon watershed or a severe winter in combination with other factors could easily eliminate this population."

CNE joined Biodiversity Conservation Alliance and other groups in filing an emergency Endangered Species Act listing petition for the dipper in March 2003. Endangered Species Act protection for the dipper would mean that its habitat - along with water quality - in the Black Hills would be protected and improved.