Modeled Top of the Wanapum Basalt Geomodel Unit (wntop_f)
The wntop_f grid represents the modeled elevation of the top of the Wanapum Basalt 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 …