46 



1981 summer, ranging from 4l to 12 percent, respectively. 

 Western slopes received ^3% usage during fall 198O and summer 

 1981. Numbers observed on flat lands were highest during the 

 summer of 198O with 30^ of the mule deer observed. Fall and 

 winter seasons were the lowest seasons for flat land usage 

 with 6 and 5 oercent, respectively. 



Use of slope : Plat and gentle slopes received the most usage 

 during spring 1980, 73/K, decreasing to a fall low of 37%, and 

 increasing again to 56^ in the I981 summer season (Table 8). 

 The flat land categories, primarily olateaus and bottom lands, 

 were least used during the fall and winter. Steep slopes were 

 utilized most heavily during the fall and winter months with 

 15 and 25 percent, respectively. Medium and steep slope usage 

 was highest in the fall, 635?, and lowest in the spring of I98O 

 at 16^. The rougher terrain provides escaoe cover during the 

 huntinpt season and protection from the wind during cold weather. 



Antelope 



Population characteristics: During the I6 months of the study 

 only 112 antelope were observed on the Sweeney-Snyder study 

 area. The rough, timbered nature of the studv area is not 

 typical of good antelooe habitat. Average group size was lowest 

 in June, 1.5 in 198O and 1.0 in 198I, and highest in March, 7.7 

 antelooe per observation (Table 9). Break-up of the winter 

 herds occurred in April. No antelope were observed on the study 

 area during the heart of the winter, i.e. December and January. 

 Most likely the antelooe wintered north of the study area in 

 the Sweeney Creek drainage. The greatest densities of antelope 

 were observed in the spring (Table 2) when 5.0 and 4.9 antelope 

 per hour of aerial survey were spotted in I98O and 1981, respect- 

 ively. 



Production data and population structures are shown in Table 10. 

 The sample size is very small and thus carries little weight. 



Distribution : All antelope observations are shown in Figure 39. 

 Two major use areas are evident. One lies along Cherry Creek 

 and includes the Tongue River-Rosebud Creek divide of the head 

 of Coal and Ranch creeks. Cherry Creek had more spring observations 

 while the upland area was primarily utilized during summer and 

 fall. No winter observations were made within the Sweeney- 

 Snyder Creek study area boundary. A second concentration of 

 observations occurred along the northern edge of the area, 

 primarily in the Sweeney Creek drainage. 



Vegetation type usage : Antelope were found almost exclusively 

 on sagebrush and grassland vegetation subtypes during the study 

 (Table 11). The only exception was one winter observation. Just 

 off the area, on a skunkbush [Rhus tfillobata) grassland site. 

 The highest percentage observed on the ponderosa pine-grassland 



r 



