The lode deposits of gold near Bannack were located near the 

 contact of igneous intrusive rocks with massive beds of Madison 

 limestone (Geach 1972). These limestone beds are in a narrow 

 belt of foothills, formed by overthrust faults (Geach 1972), 

 which extend from the Tendoy Mountains to the south, through 

 Bannack, north to the Pioneer Mountains. Bannack is located on 

 the western edge of these foothills, at the entrance to a gorge 

 through which Grasshopper Creek flows. Upstream, to the west of 

 Bannack lies the high intermountain basin of Grasshopper Valley. 



The boundaries of the study area include all of Bannack 

 State Park and some surrounding Bureau of Land Management land 

 for which a Recreation and Public Purposes Patent application has 

 been filed by the park. This patent would transfer management 

 responsibility of the BLM lands to Bannack State Park (J. Walker, 

 pers. commun.). Figure 1 is a map of the vicinity of Bannack 

 State Park, showing the boundaries of the patent application. 

 Also surveyed was an approximately 3.5 mile stretch of roadside 

 along the main access road to Bannack from the north (Figure 2). 

 The survey was originally commissioned to determine potential 

 impacts to Montana plant species of special concern caused by 

 projects proposed by the park. These projects include 1) road 

 improvements to the main access to the park, 2) a building 

 stabilization project within the Bannack townsite, and 3) a 

 nature trail along Grasshopper Creek. 



The native vegetation of the study area is highly correlated 

 with its geology and geomorphology . The ridge of Madison 

 limestone along the eastern border supports mountain mahogany 

 ( Cercocarpus ledifolius ) and limber pine (Pinus f lexilis ) 

 communities and a unique assemblage of limestone loving forbs. 

 The lower foothills to the west, underlain by Tertiary basin 

 sediments, are dominated by sagebrush (mostly Artemisia 

 tridentata var. vaseyana ) and grasses, including bluebunch 

 wheatgrass ( Elymus spicatus ) and needle and thread ( Stipa 

 comata) . The native vegetation of the Bannack townsite was 

 probably almost entirely converted during the towns occupancy, 

 but today the lowland big sagebrush (Artemisia tridentata var. 

 tridentata ) is becoming reestablished, although introduced 

 species such as Kentucky bluegrass (Poa pratensis ) and crested 

 wheatgrass ( Agropyron cristatum) are still the predominant 

 grasses. Also persisting in the townsite are many garden 

 remnants such as rhubarb ( Rheum Rhabarbarum ) and oriental poppy 

 ( Papaver orientale) . Like the townsite, the floodplain of 

 Grasshopper Creek underwent heavy disturbance in the mining days, 

 but today, riparian communities dominated by willows (Salix 

 spp.), sedges (Carex spp.), and other aquatic plants are again 

 established in some spots and even the droughty tailing piles are 

 slowly reverting to floodplain woodlands dominated by cottonwoods 

 ( Populus spp. ) . 



