This map layer is a grid map of North America including the Caribbean and most of Mexico. The map layer is an excerpt from a global assessment of forest fragmentation (Riitters et al., 2000). Each pixel value represents an index of forest fragmentation for the surrounding 81 sq. km. The map layer was created by applying spatial algorithms to a 1 sq. km. resolution map of global land cover (Loveland and Belward 1997) known as NAIGBP1_2L, obtained from the USGS Center for EROS Distributed Active Archive Center (DAAC) as part of the Global Land Cover Characteristics database (GLCC)(Loveland et al. 1991, 1999). One of six categories of fragmentation was identified for each forested pixel in North America from the amount of forest and its occurrence as adjacent forest pixels within a 9x9 pixel (81 sq. km.) window surrounding the pixel on the original land-cover map. The map layer describes one aspect of forest fragmentation at one scale. The forest fragmentation index is designed to distinguish among types of fragmentation (e.g., edges on the interior versus the exterior of a forest patch) and it also reflects differences in the absolute amount of forest present. However, no distinction was drawn between "natural" and "human-caused" fragmentation. The data available through the National Atlas of the United States are in GeoTIFF format. This is a revised version of the May 2002 map layer, with a corrected shoreline for Greenland. This map layer was previously distributed as the Forest Fragmentation Index Map of North America.