BASEMAP User defined mask .asc file

[Luigi Romolo]

Hi everybody;

I am about to create my own user defined GrADS basemaps.  Essentially, what
I am trying to do is create state maps that I can bring into the GrADS map
library.  I would also like to create my own poly.asc files for use with
BASEMAP.gs so that I can mask out everything except my state basemap.  Does
anyone have a program that would do this ????  Any progress toward a
solution to this dillema is greatly appreciated

Cheers !

Luigi Romolo