Today the Information Services Department (ISD) of the County of San Mateo launched a new open data site based on maps and spatial data, located at

This site currently features 104 Geographic Information System (GIS) datasets, available to use on as well as to download for use in desktop GIS and web GIS applications. This site will also highlight special applications such as Sea Change San Mateo County and Home For All, the County's affordable housing effort.

The County of San Mateo partnered with Esri, the industry leader in spatial data analysis platforms, to create a site that allows the County to share a wide variety of maps, applications, and spatial data with little maintenance or overhead. GIS professionals already use Esri's to find data with which to work, so the County is bringing its data via this new portal.

Available to the general public, this site allows anyone to discover and visualize maps, applications, and data. Users can easily combine data and create beautiful maps in just a few clicks. “While the public will be interested to discover new data on the Esri open data site, experienced GIS users will be able to quickly search for and download over 100 data layers upon launch,” said John Ridener, the County’s Open Data Liaison. “With the Esri open data site, the County can publish spatial data to everyone who wants it on an easy to use platform.”

The County plans to continually add additional data sets from various departments as they become available. Visitors can browse the site at: