INTRODUCTION 



This botanical study of sensitive species was conducted on lands 

 administered by the Bureau of Land Management (BLM) in McCone and 

 Garfield counties, in eastern Montana. The purpose of this work was 

 to locate and evaluate populations of potential sensitive or watch 

 species as proposed by the BLM in Montana (USDI Bureau of Land 

 Management 1993) . 



Surveys to determine the location and size of populations of rare 

 species are conducted on public lands to produce a botanical 

 conservation baseline, and to aid in resource management planning at 

 all levels. An additional goal of this study was to begin documenting 

 the general flora across the entire area. 



STUDY AREA 



Garfield and McCone counties are located south of the Missouri River 

 in eastern Montana (Figure 1) . Their county seats are Jordan and 

 Circle, respectively, and nearest cities are Glendive to the north and 

 Billings to the south. The BLM lands within these two counties are 

 part of the Big Dry Resource Area within the Miles City District. The 

 BLM lands are concentrated along the Missouri River breaks, 

 Mussellshell River breaks, and across scattered badlands. 



The bedrock geology of the study area is comprised of Tertiary 

 sedimentary formations that include the Fort Union Formation, the most 

 extensive formation and prevailing across the uplands; the Hell Creek 

 Formation mainly along northern drainageways, the Fox Hill sandstone 

 mainly in narrow bands above the Missouri River and the Mussellshell 

 River, and the Bearpaw shale below the Fox Hill sandstone along the 

 major rivers and across the southwestern end of Garfield County (Ross 

 et al. 1955). The Fort Union Formation is variably composed of clayey 

 shale, siltstone, and sandstone, with localized lenses of impure 

 limestone and lignite beds. The Hell Creek Formation is somber-gray 

 sandstone and gray shaleyey clay and mudstone. Most of the area is 

 unglaciated; only the northwestern corner of McCone County is 

 sparingly mantled by glacial till. 



A published soil survey is available for McCone County (Strom_1984) 

 which provided basis for characterizing the soil series associated 

 with target species sites, as well as copies of black-and-white aerial 

 photography for discerning unusual features in this part of the study 

 area. 



There has been little vegetation research in the project area, with 

 possible exception of range reference sites of the USDA Soil 

 Conservation Service to characterize the range sites associated with 

 soil series. Prevailing potential vegetation across the two-county 

 area is the grama-needlegrass-v.'heatgrass prairie type of Kuchler 

 (1985), which is also the single most v/idespread vegetation type in 



