The Multi-Resolution Land Characteristics (MRLC) consortium is a group of federal agencies who coordinate and generate consistent and relevant land cover information at the national scale for a wide variety of environmental, land management, and modeling applications. The creation of this consortium has resulted in the mapping of the lower 48 United States, Hawaii, Alaska and Puerto Rico into a comprehensive land cover product termed, the National Land Cover Database (NLCD), from decadal Landsat satellite imagery and other supplementary datasets.
National Land Cover Database Class Legend
11 -- Open Water
12 -- Perennial Ice/Snow
21 -- Developed, Open Space
22 -- Developed, Low Intensity
23 -- Developed, Medium Intensity
24 -- Developed, High Intensity
31 -- Barren Land (Rock/Sand/Clay)
41 -- Deciduous Forest
42 -- Evergreen Forest
43 -- Mixed Forest
52 -- Shrub/Scrub
71 -- Grassland / Herbaceous
81 -- Pasture / Hay
82 -- Cultivated Crops
90 -- Woody Wetlands
95 -- Emergent Herbaceous Wetlands
(Alaska classes not shown, including 51 (Dwarf Scrub), 72 (Sedge / Herbaceous), 73 (Lichens), 74 (Moss)).