West Mojave Plan FEIR/S - Desert Managers Group

Cumulatively, one finds there to be 274 mi 2 affected by above average trails, 324 mi 2impacted by tracks, 319 mi 2 by litter, 160 mi 2 by target shooting, 38 mi 2 by hunting, and 25 mi 2by camping. Tracks and trails are most likely to affect the MGS, as shooting has not beenidentified as a direct threat to the species. These impacts were most prevalent in the open areas,where this sort of activity will likely remain or increase under present and future management onthese class I lands.AREATable 3-36Prevalence of Vehicle-Based Disturbances in Four Areas of ComparisonSQUARE MILES, SUM, AND AVERAGE VEHICLE-BASED DISTURBANCESOBSERVED (1998-2002) IN THREE OFFICIAL AND HEAVY USE AREATrails Tracks LitterMi 2 Sum Ave Mi 2 Sum Ave Mi 2 Sum AveSpangler 121 2336 19.3 127 12140 95.6 121 4734 39.1El Mirage 19 322 16.9 19 2294 120.7 20 437 21.9Jawbone/Dove 24 370 15.4 22 406 18.5 22 381 17.3Cal. City/Rands 110 878 8.0 156 8162 52.3 156 3295 21.1Totals 274 3906 14.3 324 23002 71.0 319 8847 27.7AREA SQUARE MILES, SUM, AND AVERAGE VEHICLE-BASED HEAVY OHV USE AREATarget Hunting CampingMi 2 Sum Ave Mi 2 Sum Ave Mi 2 Sum AveSpangler 56 1006 18.0 12 13 1.1 7 18 2.4El Mirage 12 136 11.3 6 14 2.3 2 2 1.0Jawbone/Dove 16 281 17.6 1 1 1.0 2 5 2.5Cal. City/Rands 76 498 6.5 19 28 1.5 14 21 1.5Totals 160 1921 12.0 38 56 1.5 25 46 1.8Two of the 23 sites trapped for the MGS in 2002 included the El Mirage and SpanglerHills open areas (Leitner, pers. comm. 2002) where no MGS were trapped. However, theabsence of squirrels cannot be attributed to vehicle use in those two areas. El Mirage is locatedsouth of Highway 58, where no MGS were captured on eight of the nine trapping grids,including the one in the open area. Nor were any of the high concentrations of winterfat andhopsage identified in 1998 (LaRue, unpublished data) associated with either open area.Data show that there is a “spill-over” effect from the open areas, where relatively higherincidences of vehicle impacts were found in adjacent areas, compared to non-adjacent lands (seeMap 14). The prevalence of cross-country vehicle tracks north of El Mirage Open Area willprobably be reduced due to boundary fencing installed in the late 1990’s. Other areas, adjacent toJawbone and Spangler Hills, remain susceptible to open area-related impacts as no fences havebeen installed.Vehicle-based impacts may be prevalent in areas that are not adjacent to open areas.Within the MGS Conservation Area, these areas include lands within the Rand Mountains, westof Silver Lakes, within Kramer Hills, north of Hinkley, and southwest of Fort Irwin. Smallerareas also exist east and northeast of Fremont Peak, Fremont Valley, Iron Mountains north ofSilver Lakes, Superior Valley (one 4-mile region), and southeast of Harper Lake (see Map 3-17).Chapter 3 3-163