Data Resources
Thematic Data
Thematic data consists of a set of related features that are included within a single data subset. In other words, data of a common theme is generally grouped and organized within a single file structure. Within a drafting or GIS program, thematic data are grouped within a single layer (e.g., geologic units, state boundaries, soil class, etc.). A thematic map is designed to convey information about a single topic or theme, such as national highway map or a geologic map. The Thematic Data page will take you to a list of resources for digital thematic data.Topographic Data
Topographic data come in many digital forms and file formats. The Topographic Data page will take you to a list of online digital resources and provide additional information on the range of available formats.Data Sources for Individual States
Finding spatially referenced data for individual states can be a challenge. The character and accessibility of online data varies enormously from state to state. Some states have a a central clearing house for all data; in other states, different types of data are housed on different sites. Our listing of data sources for individual states provides state-by-state links to all of the major online data sources for each state.


