Groundwater Vistas (GV) is a unique groundwater modeling environment for Microsoft Windows that couples a powerful model design system with comprehensive graphical analysis tools. GV is a graphical design system for MODFLOW and other similar models, such as MODPATH and MT3D. GV displays the model design in both plan and cross-sectional views using a split window(both views are visible at the same time). Model results are presented using contours, shaded (color flood) contours, velocity vectors,and detailed mass balance analyses.