Santa Clara County is the US travel hub for tech, nationwide. And to Asia tech. And near the epicenter, if not THE epicenter of Chinese people in CA.
If it IS spreading there, it will spread everywhere very quickly unless completely shut down.
I agree with your assessment. I live in the Central Valley and my husband works in Silicon Valley. I am there at least once a week. It is an economic, social and cultural feeder to a large part of the country. Whether anything spreads depends on how this virus arrived there and how the victim/host behaved before being diagnosed. I am cautiously optimistic that people like myself can weather the storm but I have few illusions about the elderly, infirm and homeless.