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very large pastures that are either grazed in winter, or which have extensive secondary ranges. Heavy 

 spring grazing has been shown to damage populations (Lesica and Elliott 1987). In the study area, the 

 species tends to be oriented along valleys, and in several locations could be traced from headwaters 

 sporadically to Grasshopper Creek inlets over 2 miles away, disappearing where cattle use is heaviest. 

 There are also fence line contrasts that corroborate this pattern, e.g.. Astragalus scaphoides being locally 

 common on the BLM side of a fence and uncormnon in the adjoining state school land section that was 

 in poorer range condition (#008; Appendix D-5). 



Astragalus scaphoides has one of the narrowest global distributions of plant species in this study. The 

 species is locally common in Idaho (Bameby 1964, Lesica and Elliott 1987) but not in Montana. Only 

 three populations in the state have populations exceeding 5000, including the Coal Creek and 

 Henneberry Ridge populations in the Grasshopper Study Area (#016, 017). Nearly all known Montana 

 occurrences are on BLM-administered lands. BLM management of this species and of these key sites 

 are critical in its conservation. 



Spotted knapweed is encroaching in another major population (EO#008), and could become a grave 

 management problem for this species throughout the study area. 



Astragalus terminalis Wats. 



RAILHEAD MILKVETCH 



Bean Family (Fabaceae) 



The greatest numbers of railhead milkvetch were found in the Upper Madison Valley Study Area; 

 Grasshopper Study Area species information can therefore be found in the Upper Madison Valley Study 

 Area results. 



