II. IMPACTS ON THE PHSYICAL ENVIRONMENT 



RESOURCE 



[Y/N] POTENTIAL IMPACTS AND MITIGATION 



MEASURES 



N=Not present or No Impact will occur 



Y=Impacts may occur (explain below) 



4. 



GEOLOGY AND SOIL 

 QUALITY STABILITY AND 

 MOSITURE: Are fragile, 

 compactable or unstable 

 soils present? Are 

 there unusual geologic 

 features? Are there 

 special reclamation 

 considerations? Are 

 cumulative impacts 

 likely to occur as a 

 result of this proposed 

 action? 



6 



[Y] 



EXISTING ENVIRONMENT 



The proposed project area lies in the lower 

 portions of the Swan River valley. Glacial 

 moraines formed the unnamed watersheds in the 

 proposed project area. The dominant soil 

 types found in the project area are deep 

 glacial tills and glacial outwash. 



In the proposed project area, DNRC has 

 conducted timber harvesting since the 1960s, 

 mainly with the use of ground-based yarding 

 systems. Ground-based yarding displaces and 

 compacts the productive layers of soil, 

 affecting soil productivity. The most 

 effective methods to minimize the loss of 

 soil productivity is properly spacing skid 

 trails and restricting the season of use. 

 Skid trails in areas of past harvesting are 

 adequately spaced and are regenerating well . 



Soil types in the project area are primarily 

 level to rolling glacial till. The project 

 area also contains several wetland marshes 

 and fens. No area of high-risk soil were 

 identified in the project area by the 

 Flathead National Forest (FNF) Soil Survey. 

 TABLE 4-1 - SUMMARY OF DIRECT EFFECTS OF 

 ALTERNATIVES ON SOILS displays a list of soil 

 types found in the project area and their 

 associated management implications. 



Table 4-1 - Summary of Direct Effects of 

 Alternatives on Soils 



Big Slowdown Salvage 



Page CEA-5 



