site Basic Record 

 HAHNKAMP ISLAND 



From Melrose, proceed south 0.7 mile on the frontage road and park. Ford the Big Hole River to 

 the island/site. 



The site is a flat island of gravelly and sandy alluvium in the Big Hole River. Vegetation 

 ranges from Artemisia tridentata/Agropyron smithii and Agropyron smithii communities on 

 relatively xeric sites in the central portion of the island, to mesic Populus 

 trichocarpa/Cornus stolonifera and Phalaris arundinacea communities along the edges of the 

 island. A range of six salix communities is also present. 



COUNTY: Beaverhead 



USGS QUADRANGLE: EARLS GULCH 



TOUNSHIP-RANGE: 002S009W SECTION: 35 



QUARTER/ADDITIONAL SECTIONS: Portions of 35 in T2SR9V/, and 2 in T3SR9W. 



BOUNDING RECTANGLE: S: 453616N N: 453730N E: 1124042W U: 1124120U 



BOUNDARY JUSTIFICATION: The boundary follows the shoreline of the island to the south, east and west, 

 and the Mel rose/Glendale road to the north. 



APPROXIMATE ACREAGE: 170.00 



GENERAL RATING: 5 



No G3 communities or species present. 



BIODIVERSITY SIGNIFICANCE: B4 



C-ranked Agropyron smithii community (G4S3) present. Muhlenbergia minutissima (G4S1) has been 

 reported in the area. 



OTHER VALUES: V2 



The site provides high-quality riparian wildlife habitat. 



PROTECTION URGENCY: P2 



Many of the communities present are weedy (probably because of heavy grazing). Populus 

 trichocarpa regeneration is threatened by cattle browsing. Consideration of making the island a 

 riparian exclosure may be desirable. 



MANAGEMENT URGENCY: M3 



Carefully manage livestock use to minimize vegetation degradation. 



CONSERVATION INTENT: 



PROTECTION COMMENTS: 



LAND USE: The primary land use has been for livestock production. 



NATURAL HAZARDS: Fording the river poses a potential hazard. 



EXOTICS: Poa pratensis is abundant in many areas and Bromus inermis and Cirsium arvense are often well 

 represented. 



OFF-SITE LAND USES: Alteration of natural flows of the Big Hole River could change the hydrologic 

 disturbance characteristics that are vital to maintain the communities present. 



INFORMATION NEEDS: Search site for occurrences of Muhlenbergia minutissima. 



MANAGEMENT NEEDS: Many of the community occurrences have been degraded by livestock use and have 



EO ranks of C or D. However, a sufficient pool of native species is present such 

 that recovery is likely following relief from heavy grazing pressure. 



MANAGEMENT COMMENTS: 



ELEMENT OCCURRENCE INFORMATION: 



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