Modeled Thickness of the Grande Ronde Basalt Geomodel Unit (grthk_f)
The grthk_f grid represents the modeled thickness of the Gronde Ronde 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 …