75 



obsen'ations suggest that A. terminalis is palatable and may decrease under some livestock grazing 

 regimes. 



The largest Grasshopper Study Area population was discovered years earlier when its population 

 numbers were much lower and livestock use was noted as heavy. The apparent rebound in numbers 

 corresponds with improved range conditions over the 12-year interval, and reflects species' recovery 

 potential. 



The Upper Madison Valley segment contains the highest kno\\Ti numbers of this species for Montana, 

 and the species is broadly distributed here. This may be due to the area's extreme aridity and its 

 relatively low forage productivity. Increases in stocking levels or rotation frequency may detrimentally 

 affect this species. 



Knapweeds are invading this species' habitat from roadsides in the Upper Madison Valley Study Area. 

 These exotics possess a high potential for proliferation in the milkvetch's habitat both there and in the 

 Grasshopper Study Area. 



The Dillon Resource Area harbors the great majority of this species' occurrences in Montana, including 

 the largest of known populations. The species' viability in Montana hinges on BLM livestock and 

 noxious weed management decisions, and it remains appropriate for designation as sensitive. 



