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Biological Assessment for DMG Permit Renewals McClane Canyon 8 Munger Canyon Mines <br />4.1 McClane Canyon Mine Assessment Area <br />The McClane assessment area is the 2,560-acre mine permit area described in Section 3.1 and <br />depicted on Figure 2. Most of the assessment area is undisturbed pinyon-juniper woodland or <br />mixed montane shrublands in topographically complex canyon and ridge country. The soils in <br />the assessment area derive primarily from the Upper Cretaceous Mesaverde Formation (Figure <br />3), whose outcrops are visible in narrow cliff bands and ledges throughout the assessment area <br />(Photopoints 1 through 4; locations keyed to Figure 4). The western extent of the assessment <br />area includes an approximately 0.5-mile stretch of East Salt Creek and State Highway 139 (SH- <br />139). The 9.5 acres of permitted surface disturbance cut across the East Salt Creek riparian <br />corridor (Photopoint 4) and extend approximately 0.6 mile up McClane Canyon (Figure 2). <br />Elevations in the McClane assessment area range from approximately 5,400 feet at the west <br />boundary in the East Salt Creek drainage to approximately 7,000 feet at the north boundary. <br />Within the areas of permitted surface disturbance, elevations range from about 5,400 in the East <br />Salt Creek drainage to 5,700 feet at the McClane portal, and from 5,600 feet in the Munger <br />Creek drainage at the south boundary to about 5,800 feet at the emergency entry location <br />(Figure 2). Average annual rainfall in the assessment area ranges from 10 to 25 inches, and <br />average annual low and high temperatures are 31°F and 62°F (Garfield County Planning <br />Commission 2002). <br />East Salt Creek flows year-round although its flow regime along this stretch is affected <br />significantly by seasonal precipitation and spring runoff. Dominant vegetation in the East Salt <br />Creek corridor consisted of greasewood (Sarcobatus vermiculatus), big sagebrush (Artemisia <br />~~~ tridentata), coyote willow (Salix exigua), tamarisk (Tamarix sp.), and Rio Grande cottonwood <br />(Populus deltoides). Cottonwoods were confined to the creek's channel banks, were small in <br />stature, and scattered. Thickets of dense tamarisk and willow or greasewood occupied channel <br />banks, grading into stands of pure greasewood across the floodplain, and eventually to big <br />sagebrush near the floodplain-canyon side-slope transition. Shrub canopy cover across the <br />floodplain was greater than 50 percent. <br />McClane Canyon bottom supports a narrow ephemeral drainage dominated by greasewood and <br />big sagebrush near the mouth of the canyon, grading into sparse Gambel oak (Quercus <br />gambelii), serviceberry (Amelanchier utahensis), and occasional Rocky Mountain maple (Acer <br />glabrum) up the drainage near the mine portal. A portion of the Munger Canyon ephemeral <br />drainage traverses the mine permit area where it supports pinyon-juniper woodlands and mixed <br />montane shrubs on slopes with favorable aspects and soil conditions. <br />North-facing canyon slopes supported pinyon-juniper woodlands with a mixed shrub understory <br />of rabbitbrush (Chyrsothamnus nauseosus), big sagebrush, serviceberry, and shadscale <br />(Atriplex confertifolia). Cheatgrass (Bromus tectorum) and crested wheatgrass (Agropyron sp.) <br />were present in the understory, especially at the fringes of the permitted area of surface <br />disturbance. Indian ricegrass (Oryzopsis hymenoides), needle-and-thread (Hesperostipa sp.), <br />and other native bunchgrasses were also present. South-facing canyon slopes supported <br />shadscale, scattered small junipers, Cheatgrass, and native bunchgrasses observed on north- <br />facing slopes. <br />Bare soil, steep rock faces, and ledges were typical of the canyon slopes, especially on higher <br />elevation south-facing slopes. Rock surfaces were pocked and fissured, providing crevices, <br />ledges, and pockets for wildlife roost or nest sites. <br />Rare Earth Science, LLC <br />