Initially, it was only known from the one site in the Jefferson River 

 valley (Heidel 1995). Subsequent surveys within app. 40 contiguous 

 miles of the Jefferson and Beaverhead River valleys were conducted 

 in 1996 using black and white aerial photographs of the Montana 

 Department of Natural Resources and the Farm Service Agency and 

 search images from the single known site to produce the interim status 

 report (Heidel 1997). A priority was placed on surveying public lands 

 with potential habitat, conducted under land use license No. 8102 of 

 the Montana Department of Natural Resources. 



Surveys were expanded in 1997 using three effective search criteria. 

 First, a greatly-expanded aerial photointerpretation was conducted in 

 1997 among discrete areas of eight counties (Beaverhead, Broadwater, 

 Deerlodge, Gallatin, Granite, Jefferson, Madison and Silverbow 

 counties) that have broad, arid valley-bottoms with a Great Basin flora 

 and meandered wetlands. Black and white aerial photographs 

 (8"=lmile) were examined in the Farm Service Agency Offices in 

 Bozeman, Dillon, Deerlodge, and Whitehall. Xeroxes of the 

 photographs, representing almost 300 sections, were made for 

 consideration in groundtruthing and field evaluation. The meandered 

 wetlands are readily discerned on aerial photographs, but microhabitat 

 features corresponding with local species distribution can only be 

 identified on the ground. Second, available published soils maps were 

 available in Broadwater, Madison and parts of Silverbow counties to 

 look for areas wdth the two associated soil series in which all Montana 

 occurrences have been found. Note: The aerial photos that 

 accompany the Broadwater soils mapping (Olsen et al. 1977) were 

 used in place of Farm Service Agency photographs for that county. 

 Third, the southwestern Montana collection records of two closely- 

 associated species were also used as leads to potential habitat in these 

 counties. 



In addition, a single riparian corridor survey was conducted along app. 

 20 miles of the Jefferson River in the center of its overall distribution 

 but beyond the bounds of the other search criteria. The species was 

 sought unsuccessfiiUy in the successional habitat which harbors it in 

 other states, i.e., river shoreline, sandbar meadows and swales, 

 seasonally-linked oxbows, and temporarily-inundated benches. The 

 Jefferson River corridor vegetation and flat landscape setting did not 

 resemble the places where the species was found in other states. Only 

 one shoreline segment offered the same vegetation and soil conditions 

 that resembled the other places where it is found in Montana, but the 

 site was degraded and imoccupied. 



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