Montana. None of the target species occupy the prevailing prairie 

 vegetation, so the deviation in vegetation composition and 

 distribution patterns observed in the course of fieldwork have bearing 

 on the probability of finding the target species in the study area. 



Woodlands 



Woodlands are present in trace amounts in the study area, but 

 contribute significantly to floristic diversity, providing key habitat 

 for many of the peripheral plant species having Rocky Mountain or 

 eastern deciduous forest affinities. Woodlands are restricted mainly 

 to breaklands in or adjoining the Mussellshell and Missouri River 

 valleys, also extending upstream short distances along major 

 tributaries . 



Ponderosa pine woodlands are the most extensive v/oodland type on BLM 

 lands and the study area in general. They occur on ridges and north- 

 facing slopes centered along watercourses in settings which typically 

 do not carry fire. Soils are mainly derived from sandstone and other 

 coarsely-grained bedrock. An unusual pine savanna community on 

 Bearpaw shale is found at the west end of Garfield County near Highv/ay 

 200, but it barely enters BLM lands. Pine woodlands grade into Rocky 

 Mountain juniper slopes on steep, sheltered hills in the Badlands or 

 along major watercourses. Limber pine-dominated ridgetops are found 

 near the Missouri River, primarily or entirely outside of BLM lands 

 (e.g., at Hell Creek State Recreation Area). Douglas fir stands were 

 found on steep, sheltered north-facing slopes on Missouri River 

 tributaries (e.g., in Seven Blackfoot Creek on BLM lands), also 

 representing minor range extension for the species in Montana. 



Green ash woody draws are widely scattered above the Missouri River 

 and its tributaries, most commonly at coulee heads above the Dry Arm 

 of Fort Peck. Cottonwood stands are limited to the Mussellshell 

 Valley and major tributaries of the Missouri River that are not 

 inundated, as well as the free-flowing segment of the Missouri River 

 at the north end of McCone County. 



Shrublands 



Shrublands and steppe vegetation are present in alkaline upland 

 settings, and as pioneer vegetation in both wet and dry settings. 

 They are most extensive on the Hell Creek Formation and the Bearpaw 

 shale, where there are extensive Badlands outcrops and flats. 



The most common upland shrubland community is dominated by silver sage 

 and grasses including western wheatgrass and green needlegrass. More 

 localized communities of big sage and greasewood are found in outwash 

 flats; and longleaf sage, rabbitbrush, silverscale, and saltbush on 

 Badlands outcrops. Thinsoil rocky slopes are dominated by skunkbush 

 sumac, creeping juniper and yucca. 



V7illow shrub communities are uncommon along river corridors; also 

 found across impoundment backwaters. Salt cedar, which is a shrub and 

 a noxious species, is extensively invading the latter. 



