Modeled Thickness of the Overburden Geomodel Unit (obthk_f)
The obthk_f grid represents the modeled thickness of the Overburden geomodel unit at 
a 500 foot resolution. It is one grid of a geomodel that consists of eleven grids and a spatial extent polygon 
shapefile. As part of a U.S. Geological Survey Groundwater Resources Program study, a three-dimensional 
geomodel was …