Choropleth Maps

A choropleth map is a thematic map that uses colors to discribe its topic. This map is using color to discribe hey production.

http://www.agcensus.usda.gov/Publications/2002/Ag_Atlas_Maps/Crops_and_Plants/Hay_and_Forage_Crops_Harvested/Hay%20-%20All%20Hay%20Including%20Alfalfa,%20Other%20Tame,%20Small%20Grain-choropleth%20map.gif