San Francisco Bay Area Outlying Coverage

Since Bay Area cellular subscribers often travel outside the immediate bay area, it is useful to know what kind of coverage to expect in counties such as Santa Cruz, Monterey, San Benito, Lake, Mendocino, Sonoma, Napa, Solano, San Joaquin, Mariposa, Tuolumne, and Calaveras.

Santa Cruz County
The carriers with the best coverage are Cellular One (TDMA) and Verizon (CDMA, AMPS). AT&T does not offer service in Santa Cruz. Sprint has coverage in the metropolitan area and along the highway 17 corridor, but in other areas you can roam onto the AMPS network and pay roaming fees.

Monterey County
AT&T, Cingular and Verizon have coverage. Sprint has partial coverage.

San Benito County
AT&T has taken over this area from Dobson. They do provide coverage (GSM coverage is better than TDMA), though the AT&T Wireless web site claims that they do not sell service in that area (and Dobson has removed this market from their web site). Sprint and Cingular have partial coverage. Verizon provides the best coverage because it works further into the rural areas, i.e. most of the way to the Pinnacles.

I received an e-mail on 16 July 2003 which stated: 

I just got a dual mode from ATT 2 months ago (TDMA here sucks) and it works VERY well in Hollister and parts south. ATT just put a new (concrete is barely dry) GPRS switch in Tres Pinos (right behind the 18th Hole Bar- it's pegged anywhere around there. 

Transition on Hwy 25 going to/from Gilroy is poor, just like the TDMA- basically you have to hang up, wait a couple miles, then dial again so you are on the switch that you are heading towards- it does not hand off in either direction for some reason (ATT says it's Cell 1's fault, Cell 1 says it's ATT's).

Lake & Mendocino Counties
(based on posts and e-mails from Mike C.)
U.S. Cellular provides good coverage in Mendocino and Lake Counties via TDMA (will be turned off), CDMA and AMPS networks. There is digital coverage in Ukiah, Calpella, Redwood Valley, and Fort Bragg. Verizon is officially digital in all of the area except Fort Bragg and Laytonville (and those towns will be going digital very soon).Coverage has increased greatly, with solid digital coverage (with the exception of Ridgewood Summit, where Verizon is putting up a site) from Willits to SF now, even in the middle ofnowhere by Squaw Rock on the Russian River!  2 new sites have gone live recently (Hopland, Kelyseyville) with 9 more on the way (Longvale, Potter Valley, and Ridgewood summit are soon to be on).Also, US Cellular plans to have their CDMA up and running in parts of the two counties by the end of the year (they are overlaying all their existing TDMA networks nationwide with CDMA), so roaming on them should be digital soon. US Cellular recently added voice activated services, like Verizon's Voice Gear.

Edge Wireless (TDMA & GSM) has good coverage. Both networks are operational and both are available at no extra cost to AT&T customers (but not to T-Mobile or Cingular customers).

Verizon also sells service in these two counties but has poorer coverage than U.S. Cellular (though it is improving). If you are on a Verizon calling plan, and have a Lake or Mendocino county telephone prefix, then you cannot roam on U.S. Cellular (even if you are willing to pay roaming fees). You will roam onto American Roaming Network AMPS network, and pay roaming fees. If on a Verizon plan with a telephone prefix from outside the area then you can roam on U.S. Cellular and pay roaming fees (except on National Single Rate where there are no roaming fees).

Sonoma County
Verizon is the best choice for the urban areas of Sonoma County, though AT&T has better coverage on the Sonoma coast. Sprint PCS provides partial coverage. Cingular also has coverage but it is of unknown quality.

Napa County
AT&T, Cingular, and Verizon provide good coverage. Sprint PCS provides partial coverage.

Solano County
To be added.

San Joaquin County
To be added.

Mariposa County
Mariposa county is covered by Golden State Cellular, a CDMA and AMPS provider. Verizon will roam onto Golden State Cellular. Not sure if AT&T TDMA/AMPS phones will roam onto Golden State Cellular's AMPS network (last time I tried it was January 2001 and it did not work).

Tuolumne County
Tuolumne county is covered by Golden State Cellular, a CDMA and AMPS provider. Verizon will roam onto Golden State Cellular. Not sure if AT&T TDMA/AMPS phones will roam onto Golden State Cellular's AMPS network (last time I tried it was January 2001 and it did not work).

Calaveras County
AT&T and Verizon have the best coverage. Verizon has the edge due to their roaming agreement with Golden State Cellular which is a CDMA provider. On AT&T and Sprint you may be able to make a credit card call on Golden State Cellular (though I was not able to earlier this year--it asked for a credit card number but no credit card would work).