FORAGE CROPS IN NORTHERN GREAT PLAINS. 



11 



ramifications of the Yellowstone group. The differentiation into 

 belts is based on two characteristics: (1) The varying degrees of 

 darkness in the color of the soil and (2) the depth to the zone of 

 lime accumulation. 



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a a 



m 



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d <^ 



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J d 



la ® 



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si 





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In general, the soils are darkest in color in the eastern part of the 

 region and gradually become lighter to the west. The lightest 

 colored soils are in the vicinity of Shelby, Mont., and from there the 

 degree of darkness gradually increases in both directions. The degree 



