INTRODUCTION 



This report covers the second year of the Circle West wildlife 

 monitoring study coordinated by the Montana Departmenc of Natural Resources 

 and Conservation (DNRC) as described in che Circle West Wildlife Baseline 

 Study (WBS) final report (DNRC, 1978) and the first wildlife monitoring 

 report (DNRC, 1979a). The reporc period extends from March 8, 1979, through 

 February 29, 1980. 



STUDY AREAS 



As during the first monitoring period, field effort was limited primarily 

 to the 174.3 km^ (99 mile^) Mine Study Area described in the WBS, with the 

 most intensive study occurring in the 29.8 km^ (11.5 mile") Proposed Mining 

 Area. However, Northern Resources informed DNRC on August 6, 1979, that coal 

 strip mining is being considered in certain additional areas. These new mining 

 areas (with the exception of a small area east of the Dreyer Ranch) lie almost 

 entirely within the Mine Study Area; consequently, they have been studied since 

 December of 1976 but at a lower level of intensity than the Proposed Mining 

 Area. In order to begin a more thorough study of these new areas as quickly 

 as possible, DNRC obtained permission to conduct small mammal trapping in 

 these areas concurrent with the regular September small mammal monitoring, 

 and to intensity monthly on- the-ground surveys of these areas. On January 8, 

 1980, DNRC received 7.5' maps showing the boundaries of the new mining areas 

 (see Figure 1). On January 23, 1980, DNRC received a map showing the boun- 

 daries of the new Permit Area (Figure 1), which would need additional base- 

 line study. The letters X, Y, and Z are used to refer to sectors of the Per- 

 mit Area, as shown in Figure 1. The Mine Study Area vas then expanded by 

 approximately 14 sections to include a 1.6km (1 mile) buffer surrounding the 

 Permit Area, as shown in the figure. That portion of the Mine Study Area 

 which lies outside the Permit Area was considered a "control" area for some 

 aspects of the study. 



APPROACH 



This monitoring study focuses on a few key parameters which (1) are 

 indicators of overall environmental conditions and/or of year-to-year trends; 

 (2) are believed to be especially sensitive to mine-related impacts; (3) are 

 cost-effective in terms of amount of field work required, and (4) are capable 

 of being measured quantitatively with an acceptable degree of accuracy and 

 with a minimum of "noise" or unexplained fluctuation. This approach allows 

 both yearly updating of the data gathered during the baseline study and mea- 

 surement of long-term trends and variability while keeping study costs to a 

 minimum. The quantitative parameters selected for the long-term monitoring 

 study are listed below. Justification for selection of these parameters is 

 presented elsewhere in this or previous reports. 



Weather 



Annual Precipitation 

 April-July Precipitation 

 November-March Precipitation 

 Average January Temperature 

 Average July Temperature 



