tional dines of figure 3. □ = Lost Valley, 

 ■ = PREF. 



Figure 2 — Climatic isopleths in relation to the 

 distribution of the species (shading) and location 

 of the Bitterroot Range (symbols) for (A) mean 

 annual number of days with temperatures lower 

 than °C, (B) mean annual days with tempera- 

 tures greater than 30 °C, (C) average annual 

 frost-free period, and (D) mean annual precipita- 

 tion (cm) (U.S. Department of Commerce 1968). 



2 



