Upper Freeport Coal Bed County Statistics (Geology) in Pennsylvania, Ohio, West Virginia, and Maryland

This dataset is a polygon coverage of counties limited to the extent of the Upper Freeport coal bed resource areas and attributed with statistics on the thickness of...本数据集为面向县域的多边形覆盖数据集，其范围限定于上弗里波特煤层（Upper Freeport coal bed）的资源分布区域，并附带了关于……厚度的相关统计数据。