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Sufficient habitat exists in the project vicinity for a wide range of small mammals,
<br />including insect -eaters (Insectivora), bats (Chiroptera), flesh -eaters (Carnivora), gnawing
<br />mammals (Rodentia), and hares and rabbits (Lagomorpha). Both migratory and nonmigratory
<br />bats occur in the area and roost in old buildings, hollow trees, rock crevices, and caves.
<br />Carnivorous small mammals include the coyote and bobcat (both of which are found through-
<br />out the study area), the raccoon (which is common near water sources), and a variety of rodents
<br />and fur -bearers: beaver, muskrat, cottontail rabbit, pocket gopher, voles, mice, porcupine,
<br />weasel, ferret, mink, badger, striped skunk, spotted skunk, and fox. These furbearing mammals
<br />may be present in any of the vegetation communities, although they usually gravitate toward
<br />water sources.
<br />Avian species known in the general area include waterfowl, raptors, upland game birds,
<br />and a variety of smaller birds. The most common game birds are the blue grouse and turkey.
<br />Raptors reported in the vicinity include the turkey vulture, the red-tailed and other hawks, the
<br />golden eagle, the bald eagle, the prairie and peregrine falcons, the American kestrel, and
<br />several owl species.
<br />Climatically, the yearly average temperature is 32 to 45 degrees F., and there is a
<br />maximum of 100 frost -free days in a year. Annual precipitation is approximatley 18 to 20
<br />inches (USDA SCS 1976).
<br />Prehistoric land use was primarily hunting and gathering, which had little or no adverse
<br />affect on the local environment. Present day land use includes cattle grazing, hunting, and coal
<br />mining development.
<br />4.0 PALEOCLIMATE
<br />Paleoenvironmental data for the area is scant, but it is agreed that gross climatic
<br />conditions have remained fairly constant over the last 12,000 years. However, changes in
<br />effective moisture and cooling/warming trends undoubtedly affected the prehistoric occupation
<br />of the area. Based on an analysis of the area's late Quaternary stratigraphy, the geologic history
<br />of the last 18,000 calendar years in the region follows something like the following scenario
<br />(Miller 2010: Chapter 2; Conner et al. 2011:2.35-2.36). [Dates (*) are calibrated.]
<br />Late Pleistocene dissection scoured channels during the Late Glacial and deposited
<br />thick sequences of large, e.g., boulder -sized, gravel in most drainages. About 13,400 BC* the
<br />glaciers are retreating and capacity and competence decrease; the time between then and about
<br />11,000 BC* is identified by Haynes (1991) as the Clovis drought. In areas dominated by
<br />aeolian processes, deflation occurs. The Younger Dryas, from around 10,600 to 9000 BC*, the
<br />last gasp of the glacial period, took place around Folsom times. During the period, drainages
<br />are rejuvenated, surfaces stabilize, soil formation accelerates, and the late Pleistocene -early
<br />Holocene loess is slowly accumulated.
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