choropleth map

An example of a chlopleth map showing US farm acreage. Note the interval uses on bottom left corner. Each shade of red showing the amount of acreage.

http://rds.yahoo.com/_ylt=A9G_bDpwFBJJ2e4AY_qjzbkF/SIG=12msdf4aj/EXP=1226008048/**http%3A//www.jsu.edu/depart/geography/mhill/port/ps/choroplethb.html