It's true that on the ranch roads that I'm guessing you'll be riding on, there are no shoulders (you can actually use Google Maps' Street View to check out road conditions--I recommend it). And it's true that the typical motorist's typical attitude towards cyclists here is not as accommodating as it might be in the bay area.
As to whether that makes it "unsafe," we all need determine what level of risk we're comfortable with. I ride on the country roads around Austin all the time, and have been hit on them only once. You'll probably be fine.