several active shrub-covered avalanche chutes that cut through a 

 spruce-fir forest. 



The Plant Creek RNA, a 257-acre site just south of Mibooula, 

 established in 1986, represents one of the few remaining patches 

 of undisturbed old-growth montane forest found in western Montana. 

 As a result of fires and heavy timber harvesting, it is uncommon 

 to find an undisturbed, lower elevation (5,000 feet) forest of 

 300-year-old western larch and Douglas fir. 



Sheep Mountain Bog was established as a RNA in 1983, making it 

 one of the few protected bogs in the northern Rocky Mountains. 

 This 2.5-acre sphagnum moss bog was formed within a glacial cirque 

 basin at 6,280 feet, and has has served in dating vegetation 

 history through the examination of its accumulated organic 

 deposits that include pollen, spores, and volcanic ash from 

 throughout the Pacific Northwest. Also, the northern bog lemming 

 ( Synaptomys borealis), a scarce and locally distributed vole, has 

 been reported in the area. 



Geologic Features 



Nine percent of the Class I and II geologic feature sites, 

 excluding type locations, were found in the upper Clark Fork 

 drainage. Two areas are noted for their glacial moraines, the 

 first on Monture Creek near Ovando. One glacier originating in 

 McCabe Creek to the east joined another in Monture Creek, and the 

 combined glacier covered much of the valley floor north of Ovando. 

 Lateral moraines, pothole lakes, and outwash plains show the 

 extent of glaciation. Although farming has disturbed some of the 

 vegetation in the area, landforms resulting from glaciation are 

 very distinct. The second area clearly showing a glaciated 

 landscape is located adjacent to Racetrack Creek outside of Deer 

 Lodge. This area consists of a deeply glaciated valley and large 

 moraine . 



Another interesting glacial feature can be seen just north of 

 the small town of Maxville on Flint Creek. The large boulders 

 covering the ground as one heads north out of the hills resulted 

 from either an earth flow or from the bursting of an ice dam. Air 

 photos of the area indicate that the rock debris probably 

 originated in the Boulder Creek drainage, which flows into Flint 

 Creek from the east at Maxville. 



Good examples of ripple marks and mud cracks in the Belt 

 series sedimentary rocks is visible near the Flint Creek 

 Campground just northeast of Georgetown Lake. These features 

 indicate the depositional environment for the Belt Supergroup, a 

 series of slightly metamorphosed, fine-grained sedimentary rocks 

 widespread throughout northwestern Montana. The depositional 

 environment was that of low-gradient streams feeding a large, 

 shallow basin in an arid climate. The mudcracks resemble those 



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