The climatic station closest to the 

 central Montana sites is at Stanford, 

 which at 4710 feet (1413 m) , is 2000-3000 

 feet (600-900 m) lower than most of the 

 sites in the Little Belt Mountains. Thus, 

 precipitation is likely to be higher and 

 temperatures on the average lower at the 

 sites where populations occur. For the 

 period 1951-1980 (U.S. Department of 

 Commerce 1982) , the January mean 

 temperature was 20.5°F (-6.4°C), the July 

 mean temperature was 65.2°F (18.5°C), and 

 the annual mean temperature was 4 4.2°F 

 (6.8°C). The mean annual precipitation 

 was 15.3 in (38.3 cm) with May (3.01 in 

 (7.5 cm)) and June (3.07 (7.7 cm)) being 

 the wettest months. 



c. Local microclimate: Populations of 



Cirsium lonqistylum occur in open high 

 elevation meadows that remain moist from 

 snow melt into June. Lower elevation 

 populations occur in meadows near creeks 

 where the soils are more moist than the 

 surrounding uplands, but not inundated. 



2. Air and water quality requirements: Air and 



water quality requirements are not known. 



3. Physiographic province: Mapped by Hunt (1974) 

 as occurring in the Northern Rocky Mountain 

 physiographic province. 



4. Physiographic and topographic characteristics: 



Cirsium lonqistylum occurs predominantly at 

 altitudes of 5200-7500 ft (1665-2400 m) , with 

 the lowest recorded location at 4680 ft (1475 

 m) and the highest recorded location at 8040 ft 

 (2575 m) . 



5. Edaphic factors: The soils under Cirsium 

 lonqistylum populations in central Montana are 

 developed in parent materials derived from a 

 wide variety of geologic sources. These 

 include hard, coarse-grained metamorphics of 

 Precambrian age. Paleozoic limestones, 

 dolomites and shales, and intrusive igneous 

 rocks (Veseth and Montagne 1980, Weed 1900) . 

 Site-specific soil information for the sites is 

 not available, but general information 

 indicates that Cryochrepts, Cryoboralfs, and 



