The LULC data are available in two different formats. The first format was developed as a part of the Geographic Information Retrieval and Analysis System (GIRAS). This data structure evolved as the USGS developed the LULC program in the late 70's. The other format is the Composite Theme Grid (CTG) format. This format is grid cell oriented instead of polygonal. Both formats are further defined in the Appendix under GIRAS and CTG.
Extent of Coverage
Applications and Related Data Sets