GIS, Mapping, and Geospatial Data

data.gov is the US federal government's open data repository. It provides access to data, tools, and resources to conduct research, develop applications, design data visualizations, and more. You can narrow the results down to geospatial layers.

USGS Earth Explorer provides access to various data, including satellite images, lidar, orthophotos, and DEMs. NOTE: Sign up for a free account to download data.

Managed by the National Geospatial Program (NGP), The National Map Viewer provides visualization and download of all eight primary themes of The National Map data sets, including US Topo elevation data sets and historical topographic map products.

USGS National Map Apps offers several apps for accessing elevation, contour, LIDAR, land use/land coverage, and topographic map layers.

This site provides detailed administrative, legal, and statistical boundaries as well as the features used for delineating them (water bodies, roads, landmarks).

Climate Data Online (CDO) provides free access to NCDC's archive of global historical weather and climate data in addition to station history information.

NOAA Sea Level Rise Viewer Data provides links to download data associated with the NOAA Office for Coastal Management's (OCM) Sea Level Rise Viewer, including Digital Elevation Models (DEMs), Depth Rasters, and more.

MGDS is a trusted data repository offering free public access to a curated collection of marine geophysical data and metadata related to the formation and evolution of the seafloor and sub-seafloor.

The Geospatial Data Gateway (GDG) provides access to a map library of over 100 high-resolution vector and raster layers in the Geospatial Data Warehouse. It features environmental and natural resources data, allows you to choose your area of interest, browse and select data, customize the format, then review and download.