USDA-NRCS Geospatial Data Gateway (USDA-NRCS)

The Geospatial Data Gateway (GDG) of the United States Department of Agriculture- National Resources Conservation Service provides access to a map library of over 100 high-resolution vector and raster layers in the USDA Geospatial Data Warehouse. It is the one-stop source for environmental and natural resources data for the continental USA. Useful geographical datasets from a land resources planning perspective include:

1) Web Soil Survey: the official USDA soil information as viewable maps and tables for more than 3200 soil surveys, including soil series descriptions, soil characterization data, soil health and soil geography information.

2) Aerial Photography: archive with more than 70,000 rolls of film (10 million plus images), from 1955 to the present, providing coverage of most of the United States and its territories. Useful for environmental assessments, change detection, and property boundary disputes.

3) National Elevation Dataset: contains digital elevation data with 10 m (1 arc-second) ,30 m (3 arc-second), and 3 meter(1/3 arc-second) resolution. The highest resolution is obtained through LIDAR technology and available only for parts of the USA, being generated by the ongoing 3DEP project.

4) Census data: contains maps and spatial datasets related to the population of the USA. These include the Census Data Mapper, a web mapping application providing population data from the 2010 Census, reference maps (e.g. census blocks, tribal tracts, urban areas), thematic maps (e.g. population density and changes, poverty). Users with access to GIS software can use the TIGER products, which contain spatial datasets containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas.

The GDG also provides links to state-based cadaster data.