Location: Rio Blanco County
Size: 504 acres
Designated: 2009
Landowner: Private
The areas in and around Duck Creek and Shell Duck Creek house the largest and best populations of Dudley Bluffs bladderpod (
Physaria congesta) in the world. This species is ranked critically imperiled by the Colorado Natural Heritage Program (G1, S1) and listed as federally threatened under the Endangered Species Act. The Duck Creek area primarily contains these unique biological resources 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. Owned by Shell Frontier Oil and Gas, this natural area is a great example of how a state agency and a private petroleum company can work cooperatively toward the protection and preservation of Colorado's natural heritage.