Tikal, Guatemala, is one of the largest ancient Maya cities of the Peten. During the Classic Period, population densities reached 800 per square kilometer. In order to sustain such a large population, vast subsistence systems were required. To better understand agricultural methods used by the Maya, we identified areas that were agriculturally important. Our sampling strategy was to collect and analyze different soil types correlated with varying topographical and vegetative areas. Carbon isotope analysis along with soil fertility analyses were carried out to identify which areas were more likely to have been cultivated. The results were mapped, compared with a DEM layer, and analyzed using GIS. Agricultural production at Tikal is better understood since fertile soil types and preferred crop areas were recognized.