Appendix B 

 Happy Valley Soils 



Soils Analysis 



FOR THE 



Happy valley Timber Sale 

 Introduction 



The upper Flathead valley is formed by glacial scour. The dominant soil types found in 

 the project area consist of glacial till with a volcanic ash-influenced loess surface soil. 

 Geology is derived from argillite, siltite and limestone from the Belt Supergroup. 



Analysis Methods 



Soil productivity will be analyzed by evaluating the current levels of soil disturbance in 

 the proposed project area. Analysis criteria will also include soil stability risk factors. 



Analysis Area 



The analysis area for evaluating soil productivity will include DNRC owned land within 

 the proposed project area. 



Existing Conditions 



In the proposed project area, DNRC has conducted timber harvesting since the 1920s. 

 Since that time, nearly all of the state land in the proposed project area has been 

 harvested with varying intensity. All harvesting has used ground based machinery. 

 Ground based yarding affects soil productivity through displacement and compaction of 

 productive surface layers of soil. Proper spacing of skid trails and season of use 

 restrictions are the most effective methods to minimize the loss of productivity. Many of 

 the skid trails in old harvest units have adequate spacing, but some have not re-vegetated 

 well. The primary reason for the poor re-vegetation is due to use of motorized vehicles 

 on trails. Use on some of the old trails has been extensive enough that they have become 

 part of the existing road system. 



Erosion and rutting on the existing road system is severe in places, and the existing road 

 system does not meet applicable BMPs in many places. 



Soil types in the project area are classified in the Whitefish Series, and vary from nearly 

 level to gently rolling. Primary management concerns with these soils are to minimize 

 compaction and displacement. Surface soil productivity can be reduced with compaction 

 and displacement if not properly mitigated and minimized. No areas of high risk soil 

 were identified in the project area by the Upper Flathead Valley Soil Survey. No slope 

 failures were identified during reconnaissance in this area. 



Direct and Indirect Effects 



No Action Alternative 



The no action alternative would have no direct effects on soil productivity. No ground 

 based machinery would be operated under this alternative, which would leave the soil in 

 the project area unchanged from the existing conditions. 



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