Major Land Resource Areas (MLRA) and Land Resource Regions (LRR) are areas of the United States with similar geography (physiography, climate, geology, etc.), as defined by the US Department of Agriculture and the Natural Resources Conservation Service. These areas are used for large scale interstate planning. There are approximately 280 MLRAs in the United States, and its territories.
Detailed polygons of each MLRA are displayed in Google Earth. The polygons are clickable when you zoom in close enough for the detailed polygons to become visible (they are also semi-transparent) Click on a polygon to see the name of the MLRA, the name of the LRR, and a link which will load a PDF file containing several pages of detailed information about that particular MLRA and LRR.