Location: Rio Blanco County
Size: 3420 acres
Designated: 2009
Landowner: BLM
Duck Creek is the prime location of one of the rarest plants in Colorado, the Dudley Bluffs bladderpod (
Physaria congesta). This property contains two outstanding, A-ranked occurrences of this rare species that has been federally threatened under the Endangered Species Act since 1996. The large area covered by the population is due to the fact that the dip of the rock layers is the same as the grade of the stream, resulting in exposures of the Thirteen Mile Tongue of the Green River Formation that extend for miles along either side of the valley. This geologic exposure also supports a rare thistle (
Cirsium barnebyi) that is ranked as globally imperiled by the Colorado Natural Heritage Program. Because of the occurrence of these two rare species, Duck Creek is included in the ‘Dudley Bluffs Potential Conservation Area’, a Potential Conservation Area of Outstanding Biodiversity Significance (B1), as ranked by the Colorado Natural Heritage Program.
Additionally, Duck Creek contains an example of Sagebrush Bottomland Shrublands (
Artemisia tridentata ssp. tridentata / Leymus cinereus Shrubland) that is in good condition and is ranked as globally imperiled (G2, S1). This community type is rare in Colorado and its protection is important for the natural heritage of the state.