Produce the block map. The ID statement
specifies the variable that is in both the map data set and the response data
set and defines map areas. The BLOCK statement specifies the variable in the
response data set that contains the response values for each of the map areas.
CBLKOUT= specifies the color for the block outlines.
proc gmap map=maps.us data=reflib.sites;
id state;
block sites / cblkout=black;
run;
quit;