Timber harvest can increase elk vulnerability by changing the size, structure, 

 juxtaposition and accessibility of areas that provide security during hunting 

 season (Hillis et al. 1991). As visibility and human access increase within 

 forested landscapes, elk have a greater probability of being observed and 

 subsequently harvested by hunters. Hillis and others (1991) recommended that 

 effective elk security should be composed of nonlinear blocks of mature forest 

 cover (with at least 50% canopy closure) that are at least 250 acres in size and at 

 least one half mile from any open road (Hillis et al. 1991). They also suggested 

 that security cover is lacking if less than 30% of an area is composed of security 

 cover and stated that maintaining connectivity among security areas is important 

 (Hillis et al. 1991). Relationships of security cover and vulnerability for deer are 

 not well known. However, because mule deer are less social than elk, and are 

 smaller, they tend to use smaller patches of cover more effectively. It is generally 

 assumed that if the security cover needs of elk are met, then those of deer are also 

 met. Further, when elk security is demonstrated to be substantially compromised, 

 adverse effects to mule deer can also be expected (albeit to a lesser degree than 

 for elk). As with elk, affects on deer populations are skewed towards the male 

 segment of the population with regard to security. 



The proposed harvest unit provides some winter habitat for deer and elk and is 

 used during fall hunting seasons by elk. Elk were found to winter in the area, 

 with increases in use during the fall hunting seasons (Henderson and Hillis 1998). 

 Although the Project Area was not a security area for elk as defined by Hillis et 

 al. (1991), it was thought to be "de facto security" due to the limited hunter access 

 resulting from the closed gate near occupied private land along Deadman Gulch. 

 Due to the availability of movement data (Henderson and Hillis 1998), the large 

 ranges of elk and the seasonal shifts in habitat use in this area, a larger Analysis 

 Area was developed. The area used in the assessment of effects was described by 

 a polygon bounded by the Bitterroot River to the east, Highway 12 to the south, 

 the Clark Fork River to the north, and the Deep Creek/Albert Creek divide to the 

 west. This area includes two distinct herd units: the Sleeman herd unit, which 

 encompasses the Project Area, and the O'Brien herd unit (Henderson and Hillis 

 1998). 



Deadman Gulch Timber Sale Environmental Assessment 3-16 



