Cooperatives:

• Yolo County GIS Cooperative Blog
• Sacramento Area Council of Governments (SACOG)
• Yolo County GIS

• ESRI Training Center
• ESRI Glossary of GIS Terms

• URISA - Northern California Chapter
• National Emergency Number Association - NENA
• Sacramento ESRI Users Group

• Association of American Geographers
• Census
• USGS
• California Population and Housing Estimates
• About.com Geography Page

• Environmental Systems Research Institute (ESRI)
• Autodesk