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a. Koeppen climate classification: Types 

 Dfb (Canadian climate, snowy winters and 

 moderately warm summers) in the 

 subalpine and ET (tundra climate, the 

 mean temperature of the warmest month 

 above 0°C (32°F) but below 10°C (50°F) ) 



in the alpine areas above timberline 

 (Visher 1954) . 



b. Regional macroclimate: The alpine areas 

 of the Bitterroot Range are 

 characterized by exposure to strong, 

 erosive winds and low temperatures. The 

 upper subalpine, timberline areas 

 receive the highest snowpack 

 accumulations and the open, alpine areas 

 the least (Lackschewitz 1970) . 



From July 1967 to July 1969, a temporary 

 weather station was established on St. 

 Mary Peak by S. Arno and J. Habeck. 

 Because of unusual heat and drought in 

 the summer of 1967, only measurements 

 from 1969 are considered nearly average 

 (Lackschewitz 1970) . The daily mean 

 minimum temperature in January was - 

 IS.O-C (8.6°F); the daily mean maximum 

 temperature in July was 14. 7 "C (58.5°F). 



Data for precipitation are available for 

 Lolo Pass (1740 m (5700 ft.) in 

 elevation), approximately 32 km (20 mi.) 

 northwest of St. Mary Peak (U.S. 

 Department of Commerce 1982) . Over 17 

 years, from 1948 to 1964, the average 

 annual precipitation was 1320 mm (52 

 in.); the maximum amount was 1780 mm (70 

 in.), and the minimum amount was 790 mm 

 (31 in.) (Lackschewitz 1970). 



Local microclimate: Lesauerella humilis 

 occurs generally on open, exposed sites 

 with a southerly or westerly aspect. 

 These sites usually have low winter snow 

 cover and, during the growing season, 

 are warmer and drier relative to other 

 microsites on these peaks. 



2. Air and water quality requirements; 



Unknown. 



