Generate the block maps for each region. MIDPOINTS= defines the midpoints of the ranges described in the legend. NAME= is a full 8 characters ending in 1 so the incremented names match the regions. NAME= specifies the name of the first catalog entry. Because BY-group processing generates multiple graphs from one BLOCK statement, the name assigned by NAME= is incremented to provide a unique name for each piece of output. These names are automatically assigned to the GIF files. DES= specifies the description that is stored in the catalog and used in the Table of Contents. Because BY-group processing is used, the same description is assigned to all the output. 
proc gmap map=maps.us data=newsites;
   by region;
   id state;
   block sites / midpoints=(12 37 62 87 112)
                 legend=legend1
                 shape=cylinder
                 blocksize=4
                 coutline=black
                 des='State Maps'
                 name='states01';
run;
quit;