2010-05-07_PERMIT FILE - C2009087A (4)

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feet.. For some of the same reasons listed for Debris milkvetch, Starveling milkvetch is not known • in Routt County and unlikely to occur in the study area. Osterhout milkvetch (Astragalus osterhouth) is a Colorado endemic species found in the Muddy and Troublesome Creek drainages of Grand County. These drainages are characterized by highly seleniferous / gypsiferous, grayish -brown clay soils derived from shales of the Niobrara, Pierre and Troublesome Formations of the Upper Cretaceous and Tertiary. Osterhout milkvetch occurs on moderate slopes and has also been documented growing up through sagebrush. The elevation range within which this species is found is 7,400 to 7,900 feet, within the upper limits of the elevation range of the Study Area. Shales of the Study Area are considerably less gypsum - rich and this, along with the fact that A. osterhoutii has never been found outside of its few localities in central Grand County, makes its presence in the Sage Creek study area very doubtful. Ligulate feverfew (Bolophyta ligulata) is found in Moffat and Rio Blanco Counties in northwestern Colorado and in Utah on barren soils derived mostly from the Uinta Formation at elevations ranging from 5,400 to 6,500 feet. It occurs at Raven Ridge near Mormon Gap, west of Rangely with Eriogonum ephedroides and Penstemon grahamii. The much lower elevational range for this is species (not within the range of the Study Area) means that the conditions of its occurrence are warmer and drier. The Uinta Formation (Eocene) is also younger than the Cretaceous -aged shale and sandstone found in the Study Area and differs in ways described above. Ownbey thistle (Cirsium ownbeyi) is found in the Uinta Basin in northeast Utah, southwest Wyoming and in Moffat County in northwest Colorado in juniper, sagebrush and riparian communities at 5,500 to 6,200 feet. The substrate on which it is commonly found includes gravelly alluvium, talus, or sandy slopes as well as on sandstone and limestone (of the Weber and Morgan Formations, respectively). These formations are of Pennsylvanian age, much older than the rocks of the Study Area, and are usually exposed at the bases of steep cliffs. The locations of occurrence of the thistle are often in association with slot canyons, in alcove seeps and abandoned stream channels. Cretaceous age sandstones of the study area are not configured as large cliffs with basal seeps; slot canyon habitat conditions necessary for this species are absent. Twentymile sandstone exposures, while sometimes expansive, are not in general possessed of seeps. Uinta Basin spring - parsley (Cymopterus duchesnensis) is found in Utah and in northwest Colorado in Moffat and Rio Blanco Counties. It is found in cold desert shrub, sagebrush and • 28