regions with a cool, moist climate. This area's arid climate and 

 associated upland plant communities combine to make Pine Butte 

 Swamp botanically unique. 



A regionally endemic plant found on Marias Pass is peculiar 

 moonwort ( Botrychium paradoxu m). This tiny fern is known from only 

 four locations and is a candidate for U.S. Fish and Wildlife 

 Service and Montana Rare Plants Project listing for endangered 

 species status. 



Craw's sedge (C arex crawei) is another sparsely distributed 

 plant species in this drainage, known to grow only on the gravelly 

 limestone soils along the Teton River. One reason the Montana 

 Rare Plants Project lists Craw's sedge as a threatened species is 

 that oil and gas exploration is currently occurring within this 

 area. 



Geologic Features 



Even though the east slopes of Glacier National Park, the Bob 

 Marshall-Great Bear wilderness complex, and an Indian reservation 

 along the Rocky Mountain Front were not assessed, these drainages 

 still contained seven percent of the Class I or Class II geologic 

 sites, excluding type locations, identified in the study. Further 

 study is likely to reveal additional outstanding sites. 



The spectacular features associated with formation of 

 mountains in the Overthrust Belt stand in sharp contrast to the 

 subtle glacial features at the lower elevations. The area adjacent 

 to the Sun River Canyon northwest of Augusta exemplifies the 

 processes that occurred during the formation of the Lewis and 

 Clark Range. The Sun River has cut a canyon, exposing large slabs 

 of rock which have been shoved on top of each other in a process 

 known as thrust faulting. In a road-cut in the canyon, slabs of 

 older, light gray colored Madison limestone have been pushed over 

 a younger, dark gray shale. This illustrates the faulting process 

 that in this area repeatedly thrust layers of rock over the top of 

 others, much like shingles on a roof, building the steep mountain 

 ridges of the Overthrust Belt. 



A striking modified trellis drainage pattern has developed to 



the north of the Sun River. The drainage pattern follows straight 



parallel faults and/or jointing patterns on either side of Castle 

 Reef, a prominent ridge. 



A vast inland sea lapped up against the mountains during the 

 late Cretaceous period and in the sediments deposited along this 

 sea, paleontologists, have recently unearthed a nesting area of 

 the dinosaur Maiasaura peeblesoru m. Most amazing is that the area 

 contains a rare dinosaur nesting area with fossilized eggs, 

 embryos, and young. These fossils are on display at the Museum of 



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