state, Burlington Northern, Kennecott Copper and ASARCO 

 ownership, while St. Regis, private and federal interests 

 account for 9, 11 and 78 percent of the land ownership, 

 respectively. The ASARCO copper-silver mine, known as the 

 Troy Project, is in the southern half of the area. The study 

 area includes the Ross Creek Giant Cedars Scenic Area and a 

 portion of the proposed Scotchman Wilderness Area. 



Topography 



The broad alluvial Lake Creek and Bull River valleys 

 bisect the West from the East Cabinet Mountains 

 The last continental glacier of the Pleistocene epoch rose 

 to the 1,370 m (4,500-foot) level and extended to the gentle 

 divide between the Lake Creek and Bull River valleys which 

 drain in opposite directions to the Kootenai and Clark Fork 

 rivers, respectively. The smoothed mountain bases and deep 

 alluvial sediments of the Lake Creek Valley are testimony to 

 the continental glacier while the cirque basins and hanging 

 valleys of the peaks are products of alpine glaciation. 



Over a dozen peaks in the West Cabinets rise from the 

 700 m (2,300-foot) valley floor to over 1,820 m (6,000 feet). 

 The lowest topographical point in Montana (557 m or 1,828 

 feet) occurs immediately north of the study area where the 

 Kootenai River leaves the state. 



Mount Vernon (Figure 2), the site of the mine development, 

 is located 11 km (7 miles) from the Montana-Idaho border. The 

 Mount Vernon-Spar Peak ridge lies to the west of Mount Vernon 

 (cover photo shows Mount Vernon in the foreground. Spar Peak 

 in the center background and the mountains of Idaho in the 

 distance) , while Ross Creek skirts the mountain to the south 

 and empties into Bull Lake which borders the mountain on 

 the east (Figure 3) . Lake Creek drains north out of Bull 

 Lake and is fed by Stanley Creek which flows from the north 

 face of Mount Vernon. 



Climate 



The Pacific maritime air mass controls the climate of 

 the Cabinet Mountains although on occasion an arctic air 

 mass will push over the Continental Divide to influence 

 winter weather. Temperatures vary from -32° to 41° C (-25° 

 to 105° F) at Troy, resulting in a mean annual daily tempera- 

 ture of 5.9° C (42.6° F) (National Weather Service, Troy 

 Ranger Station) . 



Precipitation levels range from just under 100 cm (40 

 inches) near Bull Lake to near 500 cm (200 inches) at the 

 high elevation ridges, which occur primarily in the form of 



