I've been a frequent traveler within California state the last few months. I live in San Diego county and visit relatives in Northern California often; a town called Union City. Whenever I am there I am limited to one bar, which equates to calls going straight to voicemail, or if I'm able to receive them, very choppy conversations that end up being dropped. It was reported about 10 months ago that it was a tower outage in that area. The last time I visited this area was this past Labor Day to have the exact same experience.
drop a zip code and closest cross street to the location youre normally at while up there so someone can look at the towers surrounding that area.