Block diagram of a solid model created with Viewxsxn's projection algorithm using a DEM and geological map.  The cutaway is a cross section drawn North to South across the Mahantango watershed in the Valley and Ridge of PA, illustrating the method of distributing pinched-out Modflow nodes within the outcrops of lower layers (see manual for details).  Geologic top surfaces generated in Viewxsxn are shown numbered 1 to 10 in square boxes drawn on each geologic top.  Modlfow layers are shown numbered 1 to 4 in layer-centered circles representing model nodes.  Drafting Credit: Heath Ward, Geotrans Inc. Brookfield, WI