The difficulty with this series is that some map units, currently described as Miles series, do not fit within the range of characteristics (ROC) given in the official series description (OSD).  This series has been mapped across several different parent materials (residuum, old alluvium, young alluvium, and aeolian) and geologic landforms.  These different parent materials, each impart unique characteristics to soils.  

Field descriptions, chemical, and physical properties of twelve pedons (three on each parent material) were analyzed to fully characterize these soils, and determine if they were in fact Miles series soils. Characteristics of each pedon were compared to the Miles ROC and to each other.  From this comparison, a percent match was developed illustrating the tested differences between soils of different parent materials concerning their likeness or difference to the Miles ROC.  A model was then developed within the study site counties and extrapolated over the mapping extent of current Miles series soils in Texas.  The model shows probable areas where each parent materials characteristics’ may be more pronounced.