2016-12-23_PERMIT FILE - C1982056A (8)

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occur at the rate of two people for each car, the maximum access traffic level would be reduced to approximately 200 round -trips per day. Shift changes for the access traffic are expected at 7:00 am, 3:00 pm, and 11:00 am. However, there is a possibility 40 that each of these changes may be modified. The amount of access traffic for each shift change during peak traffic years (1992 -2015) would be approximately 278, 278, and 238 cars on the access road around the time of each 7:00 am, 3:00 pm, 11:00 am shift change, respectively. These numbers would be halved if two - for -one car- pooling occurs. The total magnitude of elk and mule deer migration through the permit area and use of critical winter range in the permit area has not been well documented. General observations made by Terrell Johnson (the Applicant's wildlife biologist) during aerial surveys for the general area indicate that the greatest numbers (400 -500) of elk occur in Twentymile park during migration in late fall and early winter. As winter progresses and snow levels in the park increase, most of these animals move on to wintering areas to the west of the permit area, although some remain in critical winter range on the permit area (see Map 19, Elk Biological Features). There is less known concerning the migration of mule deer through Twentymile park, but numbers of migrating mule deer in the park are thought to be significantly less than those observed for elk. In the spring, elk migrate back to summer ranges, but not as many are observed passing through the permit area due to their tendency to stay along the mountain shrub zones along the perimeter of the park. A summer population of elk also resides in the foothills along the northwest boundary of the permit area. A scattered population of mule deer inhabit the foothills around the perimeter of the permit area from spring to fall until snow levels force them into their winter range as shown on Map 20, Mule Deer Biological Features. Most big game road -kill studies have focused on stretches of major highways where a high incidence of mule deer /vehicle collisions has been documented. Myers and Reed (n.d.) in their study of deer /vehicle collisions throughout Colorado found that 53.2 percent of deer road -kills occurred between sunset and four hours after sunset. Only 9.7 percent were killed from three hours before sunrise to sunrise, and an additional 17.6 percent were killed • at other times of the night, for a total of 80.5 percent killed from sunset to sunrise. Myers and Reed (n.d.) also presented data that the majority (87 percent) of mule deer /vehicle collisions occurred at highway speeds greater than 40 mph and that 70 percent of all collisions occurred at speeds greater than 50 mph. In a study along High 82 south of Glenwood Springs, 52 percent of the deer fatalities occurred between 6:00 and 10:00 pm (Reed 1969). Reed (1969) also found that the sections of highway where the greatest number of deer were killed did not always correlate with the sections of highway where the most live deer were counted during night spotlight surveys. Reed (1969) concluded that, in order to identify problem road -kill areas, a knowledge of the magnitude and location of deer road -kills is needed in addition to knowing where deer congregate along a highway. It is assumed that the conclusions made in these studies would also be applicable to elk, but few studies focusing on elk/vehicle collisions could be found. The general lack of studies on elk road -kills may be an indication that the frequency of elk/vehicle collisions is much less than that for deer /vehicle collisions. This could be a result of an elk's much greater size (making it easier to see and avoid at night) and/or be related to different aspects of an elk's behavior along roads as compared to deer. In studies by Ward et al. (1976), it was found that elk were more sensitive to traffic than were mule deer and pronghorn. They noted that elk preferred to stay at least 0.25 mi (400 m) from moving traffic, and that most highway crossings by elk occurred at night during low traffic periods. Elk avoidance of roads is more pronounced for main roads and roads that pass through open vegetation types (Perry and Overly 1975). Ward et al. (1980) showed that elk preferred to cross roads where the slope perpendicular to the road was less than 20 percent. This preference for shallow slopes when approaching a road would increase their visibility to approaching motorists, thereby reducing the potential for collision. Based on the information presented and discussed above on elk and mule deer numbers in Twentymile Park, it appears that the greatest potential for big game road -kills may be associated with elk during fall migration. A low potential would be expected for spring migrating elk and for wintering elk and mule deer where haul and access roads travel in proximity to critical winter range. The actual magnitude of these potentials is impossible to derive • without baseline information on the number of road -kills versus traffic levels. In the studies reviewed, no attempts were made to project number of road -kills versus increased traffic levels. Variables such as weather, changes over time in animal movement and numbers, timing of traffic levels, topography, etc. make it extremely difficult to make such projections. Historically, areas in Colorado that have had the highest incidence of mule deer /vehicle collisions RN08 -05 2.04 -69 03/12/10