GIS

Open data hosted by the United States government. Data exists on a wide range of subjects, including geographical data.

Data map site maintained by the USGS. Map data can be downloaded in a variety of formats

Data sources provided by the National Park Service.

Site maintained by NASA for open data. Data can be downloaded in by variety of formats and topics

A USGS repository site that hosts a variety of data and in different formats.

A site hosted by the USDA on environment and climate data organized by state and county.

GIS data hosted by the CDC

Mapping files provided by the US Cenus. Includes TIGER and KML (Google) mapping data files.

US Census data that can be exported in Excel or CSV formats

The Ohio Geographically Referenced Information Program (OGRIP). OGRIP maintains the GIS Support Center, which provides GIS support activities to state agencies and has data that can be downloaded

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.

GIS data hosted by the Bureau of Land Management

A wiki based site that allows access to global GIS data.

Site offering interntional maps and data

Site offering data on worldwide content