Plains phlox (Phlox andicola) is locally common on 

 gently rolling sandhill slopes under a sparse canopy of 

 Elaeagnus commutata (silverberry) [Plot 

 NHMTECRA97SC0003] where only the vestiges of 

 flowers remained at the time of visit. It was occasional 

 in the best condition grassland habitat of Big Island, as 

 found on a steep, north-facing slope. It may be under- 

 documented in the sandhills area because it is 

 inconspicuous except during its early flowering, but 

 there is not enough information to confirm or refute 

 this idea at present. 



OVERALL BIODIVERSITT SIGNIFICANCE: 

 The Medicine Lake Sandhills are part of the largest 

 sandhills in Montana, followed by the Centennial 

 Sandhills in southwestern Montana which overlaps 

 with Red Rock Lakes NWR. These landscapes, and 

 their dune system in particular, constitute highly 

 significant landscapes, harboring uruque plant 

 conununties and rare species. 



This characterization is at best a preliminary highlight 

 of the sandhills vegetation and rare plant species. 

 Wildlife values were not evaluated. 



OTHER VALUES: 



Archeological and cultural values are often associated 



with sandhills. 



problems could be exacerbated without close control of 

 management and weed population responses. 



Portions of the sandhills native communities are 

 overwhelmed by dense populations of increaser species, 

 for example, sage wort (Artemisia campestris) , brittle 

 prickly-pear (Opuntia fragilis) , flixweed tansymustard 

 (DescuTainia sophia), and pinnate tansymustard (D. 

 pinnata) that may have resulted from past grazing 

 practices. Leafy spurge (Euphorbia esula) is present in 

 widely-scattered patches and spurge flea-beetles have 

 been released in an effort to control it (Rabenberg pers. 

 commun.). Canada thistle (Cirsium arvense) and other 

 exotic species like smooth brome (Bromus inermis), 

 Japanese brome (B. japonicus), and crested wheatgrass 

 (Agropyon cristatum) are present in low numbers. 



Reintroducrion of appropriately timed fire may possibly 

 be a management option to consider in contaiiung 

 nearby weeds, reducing litter accumulation, setting 

 back woody species, and stimulating forbs. 



The undeveloped areas of natural spring and seep 

 features and associated riparian habitat that were noted 

 are in relatively good ecological condition and are 

 among the segments of the landscape warranting closer 

 investigation. Water developments below them 

 reduced grazing pressure in the hills above. 



LAND USE: 



The area has a long history of grazing by livestock. 

 Grazing leases were recently cancelled on the area. 

 Upland segments near roads have been planted into 

 crested wheatgrass (Agropyron cristatum). 



MANAGEMENT COMMENTS: 

 Widely-scattered patches of leafy spurge (Euphorbia 

 esula) have been identified by Refuge personnel 

 (Rabenberg pers. conmiun.) There are several spurge 

 flea-beetle release sites in the Sandhills. 



Prior to the settlement, this landscape was maintained 

 in various successional states by periodic disturbance, 

 mostly via buffalo, pocket gophers, fire and wind. The 

 processes operative here are probably analogous to 

 those within the Centennial Sandhills. Studies have 

 demoristrated for the Centermial ecosystem, that 

 without periodic disturbance and with the healing of 

 existing blow-out and deposition surfaces, the result is 

 reduced community and species diversity, particularly 

 of rare species associated with early serai states (Lesica 

 and Cooper 1999). Cattle have served as surrogate 

 disturbance agents in the Centennial system and in the 

 Medicine Lake Sandhills in some measure. Weed 



Tepee Hills Research Natural 



Area 



environment: 



Tepee Hills is developed on a till/outwash plain that 

 has been down-cut by an abandoned meander charmel 

 of the Missouri River. It straddles the crest of the 

 slopes above Medicine Lake, with maiiJy south-facing 

 slopes mapped as Zahill clay loam, steep (Richardson 

 and Hanson 1977) that have overlying gravelly, cobbly 

 water-worked deposits of Raxville gravel (Witkind 

 1959) . The center of the RNA is dissected by a coulee. 

 The RNA comprises only 50 acres but with the 

 variation in relief, aspect and soil depth, a range of 

 environments are represented. The semi-arid 

 continental climate has peak precipitation in June 

 followed by July and May, and a mean aruiual 

 precipitation of 13.25 inches (Climate data from 

 Medicine Lake, Western Regional Climate Center, 

 1911-1997). 



49 



