2018-01-23_PERMIT FILE - C1981041A (4)

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3.0 RESULTS AND DISCUSSION 3.1 ENVIRONMENTAL CHARACTERISTICS The climate of the area is arid to semi-arid, with a precipitation at Palisade of about 9 inches a year. See Table 1. Precipitation at Palisade is distributed somewhat uniformly throughout the year, with a s I i ght peak dur i n~y'^.;5ep'~'EtabeLSy -~R$..nG~fjee . The growing season i s relatively long, extending from the beginning of April through the end of October, Z00 days. The Colorado River, flowing southwesterly, bisects the permit area. Numerous ephemeral streams in narrow, steep-walled canyons drain the permit area. Jerry Creek and Coal Creek flow easterly to the Colorado while Rapid Creek and an unnamed stream flow north and westerly, The topography is rough and steep with sheer cliffs hundreds of feet high common to much of the area. Mesas are common above the 6,000 foot elevation. There is one extensive mesa at the 5,000 foot elevation just to the east and south of the Roadside Mine. The elevation ranges from a low of 4,800 feet along the Colorado River to a high of about 7,300 feet. 1 The geology of the permit area is characterized by sandstones and • shales. The three study areas are all within the Mesa Verde group of the Cretaceous age. Younger formations above respectively include the Wasatch } and Green River, both of Tertiary age. 1 The lower elevations of the permit area are mapped as saltbush- * •greasewood by Kuchler (19661 and as saltbush by ShelFord (19631. Higher !] elevation potential natural vegetation are identified as mountain mahogany- oak shrub by Kuchler (19661 and as pinyon-juniper by Shelford (19631. ~ These mappings may accurately depict the regional climax vegetation types but are not of sufficient detail to reflect vegetational changes related ~ to exposure and substrate variations. ' The permit area and adjacent sites are characterized by nine different vegetation types. A riparian woodland with cottonwoods Pvpu.(ua de.Ltvide.~, wi I lows Sa.lix spp., skunkbrush qua davmatica ssp. #~ei.Cvbata, and chokecherry • /oaunua v<agiru ana is present in moist habitats along the Colorado River and extends as a narrow band into the tributary drainages. Moist Stream • drainage habitats along the Colorado River and its tributaries with salty soils as well as saline seeps on some slopes are characterized by a black greasewood $aacvGatue veitm<cu.Catu~ vegetation type. Fourwing saltbush • A#icipC¢x cnne~cvnn, alkal i seepweed $uaeda cf. ,fiuvltiw~a, and cheatgrass l3avmue #ectvzum are also common in this vegetation type. A rubber rabbit- ! brush Ch~~evthamnua nau4evau~ vegetation type occurs on streamside distur- ~_ bances in Jerry Creek and Coal Creek. This linear vegetation type, too small to map, is contained within the greasewood vegetation type. • The steep slopes, dry and often unstable, are characterized by a ' shadscale shrubland vegetation type. This community occurs on all slopes -5-