Happy #GISDay! Today we celebrate how geographic information systems (GIS) are being used across the globe to make a difference.
While a map is a drawing showing a limited number of things – roads, streets, county lines, etc. – an entire database of information is connected to a GIS. It’s an intelligent map that lets the user add or subtract, calculate, or analyze spatial information.
This particular GIS Day holds special significance to the California Department of Conservation (DOC). One of our GIS products is being considered for inclusion in the ESRI Map Book, Volume 35, an annual publication by the top GIS software maker. Map Book highlights the year’s top maps and mapmakers that have used GIS technology to help government, business, or citizens.
Our map, titled, California State Geology & Important Farmlands, captures the diversity of the DOC’s work by blending data from two of our divisions: the California Geologic Survey (CGS) and the Division of Land Resource Protection (DLRP).

Data from the two divisions make a visually striking combination that highlights the complexity of the state’s geology and the intersection between that geology and rich farmland.
The map also illustrates the interconnectivity of the department’s work across its various divisions and the importance of GIS to DOC’s mission.
Nathaniel Roth, DOC’s GIS Coordinator, created the dynamic piece.
“You can see all the state’s farmland falls into the quaternary alluvium of the state’s geology – which basically means the stuff washed down from the mountains relatively recently to fill in the floor of the valley. It ends up making great farmland.”
Continued Roth: “They’re patterns with reasons to exist the way they do. I knew that they should overlay well. I didn’t realize that it was going to fill out quite as nicely as it does.”
California State Geology & Important Farmlands was created to showcase the role DOC plays in generating earth science tools that help decision-makers and planners to conserve natural resources.

CGS maps the intricate geology of California, including mineral resources and geologic hazards such as faults and landslides. It translates these scientific data for various stakeholders, including regulators and planners.
The farmland data was tracked by the Farmland Mapping and Monitoring Program in the DLRP, which helps inform efforts across the state to conserve agricultural land and ensure that California remains at the forefront of US agricultural production.
Celebrate GIS Day with us by exploring more of DOC’s GIS maps and mapping tools at maps.conservation.ca.gov! To get you started, here are direct links to our most popular maps:
- EQ Zapp: California Earthquake Hazards Zones
- Geologic Map of California – data was used for the map featured here!
- Fault Activity Map of California
- Well Finder