Endangered Species

Non-Native Species
Our riparian areas are threatened by numerous plant species that are not native to the Rocky Mountains. Of particular concern are the tamarisk (Tamarix species), or Salt Cedar, and the Russian olive (elaeagnus angustifolia).

On the tail end of a drought, local, state, and national efforts are being undertaken to determine what the water consumption effects of non-native riparian species are on our water supplies. It is estimated that a mature tamarisk tree will use up to 1 additional foot of water compared to a native stand of cottonwood. Tamarisk is seldom seen above 6-7,000 feet, but has been identified and removed from Pitkin County in the past couple of years in the Crystal River drainage.

Russian Olive
Russian olive is of concern in the arid west because it also consumes water at a higher rate than native vegetation. Eradication of this invasive species of plant is difficult due to its wide seed distribution and long seed viability.

Threatened & Endangered Species
Before a plant or animal species can receive protection under the Endangered Species Act, it must be placed on the federal list of endangered and threatened wildlife and plants. An endangered species is one that is in danger of extinction throughout all or a significant portion of its range. A threatened species is one that is likely to become endangered in the foreseeable future.

The U.S. Fish & Wildlife Service (USFWS) also maintains a list of plants and animals native to the United States that are candidates or proposed for possible addition to the federal list. All of the USFWS's actions, from proposals, to listings and removals (delisting), are announced through the Federal Register.

Species of Special Concern
Pitkin County does not contain any federally listed threatened or endangered species. However, many lakes and streams contain Colorado River Cutthroat Trout, which is considered to be a Colorado species of special concern due to its limited numbers and fragile ecosystem requirements. The ways we operate many of our dams and reservoirs are dictated by the presence of these fish. Minimum flow requirements are set for the fisheries in the Roaring Fork and Frying Pan rivers and water that might be used for drinking or irrigation purposes can be required by law to remain in the stream to guarantee that these minimum flows are met.

Colorado Endangered Species
  • Boreal toad - Bufo boreas
  • Lynx - Felis lynx Canadensis
  • Wolverine - Gulo gulo
Colorado Threatened Species
  • American peregrine falcon -Falco peregrinus anatum
  • Bald eagle - Haliaeetus leucocephalus
  • Golden eagle - Aquila chrysaetos
  • Osprey - Pandion haliaetus
Colorado Special Concern Species
  • Colorado River cutthroat trout - Oncorhynchus clarkii pleuriticus