Overburden above the Hanna 77, 78, 79 and 81 coal zones, Hanna Basin, Wyoming (ha*ovbg)

These ArcView shapefiles contain representations of the overburden thckness above the Hanna 77, 78, 79 and 81 coal zones in the Hanna coalfield, Hanna Basin, Wyoming....本批ArcView形状文件（ArcView shapefile）呈现了美国怀俄明州汉纳盆地汉纳煤田内汉纳77号、78号、79号及81号煤层组上方的覆盖层厚度分布情况。