Update [6/3/2009]:

I've moved my site to HostMonster.com because the geniuses at google have decided to disable javascript on their webhosting platform. Very odd, since googlemaps uses javascript....

The big enhancement this time, other than a few more cell sites, is that maps are now split into regions of the Bay Area, to help folks with slow browsers or computers. For fastest performance on javascript heavy sites, check out Chrome by google (go figure).

Central     North     East     South     West     All

Please send any comments, additions or corrections to sfocellsites (at) gmail.com.


Update [5/25/2009]:

I now have about 1,550 cell sites in the greater SF Bay Area for T-Mobile, and about 1,150 sites for AT&T.  T-Mobile cell sites are in pink, or brown if they require more research.  AT&T sites are in blue, or green if they require more research.

The big enhancement this time, other than more cell sites, is that Cell IDs are now available by holding the cursor over the site marker.  Where a carrier has accidentally reused a Cell ID I have put a "b" on the end of the second site with the same number.  For sites I believe exist, but have not been able to visit yet, Cell IDs are something like "SJ-1" or "SF-3".

AT&T data is only partially updated these last few years, so some areas are current and some may be missing a few new cell sites.  It's hard to keep up with AT&T because, unlike T-Mobile, they are not so proud of their new coverage (and thus old coverage weaknesses)  and therefore keep their new sites secret.  AT&T coverage maps are also sketchy, making it hard to spot improvements in coverage.  I have added many 850-only sites, now that I have a Nokia 6340i too.

Please note that many AT&T and T-Mobile cell sites are co-located.  This will not be readily apparent until you zoom in several levels (3-5).  The search feature will do the first 3 levels for you while focusing on your area of interest.

Please send any comments, additions or corrections to sfocellsites (at) gmail.com.


Update [12/27/2007]:

The original site and below text were published mid 2006.  This year I'm using T-Mobile, so I decided to gather similar cell site data for T-Mobile.  So far I've got about 700 cell sites in the central SF Bay Area for T-Mobile, with more to come in 2008.  T-Mobile cell sites are in pink, or brown if they require more research.  AT&T sites are just in blue on the new map, regardless of TDMA status, or green if they require more research.

AT&T data is only partially updated since 2006, so some areas are current and some may be missing a few new cell sites.  It seems like AT&T is putting more energy into 3G than into better coverage at this time, so there are probably not too many sites missing.

Please note that many AT&T and T-Mobile cell sites are co-located.  This will not be readily apparent until you zoom in several levels (3-5).  The new search feature will do the first 3 levels for you while focusing on your area of interest.

cell site map with AT&T and T-Mobile


Original Info [mid-2006]:

Off and on for the past 2 years or so I've been wandering around the Bay Area finding AT&T cell sites.  My initial target was the 9 Bay Area counties, but I recently extended the search into San Benito, Santa Cruz and northern Monterey counties when I couldn't find 1,000 sites in the Bay Area.  Since I've now covered basically the entire target area, except Carmel, and achieved my goal of 1,000 sites, I decided to share my findings with others who might be interested.

My tools are simply two Nokia phones with Field Test (Network Monitor) enabled - a 6560 for TDMA and an 8290 for GSM - and pencil and paper.  Yes, that means GSM 850-only sites would have been missed.  I believe there may be a few 850-only sites at this time, but not too many.

The map has a colored marker for each site.  Blue means a site which has (or had) TDMA, and red means a newer site with GSM only.  Green and orange are variants of blue and red respectively, when a site still requires more research.

Locations should be within a few hundred feet for sites in the inner Bay Area, but  may be 1,000's of feet off for sites in West Marin, Sonoma, Napa, Solano, San Benito, Santa Cruz and Monterey counties.  Those areas will eventually be fine tuned by drilling down on the satelite maps, but it takes time I don't have right now.

Other remaining tasks include:

  • enhancing the information bubbles with GSM site and LAC numbers, as well as TDMA site (sector) numbers.  [When Google Pages gets a better file upload tool that should be easy.]
  • adding LAC boundaries to the maps
  • making area sub-maps
  • making a searchable list of cell site numbers

Information on this website is copyrighted and for entertainment purposes only.  Please enjoy it, and take it in the spirit in which it was intended.

Please send any comments, additions or corrections to sfocellsites (at) gmail.com.

12 counties cell site map