Legal Question in Real Estate Law in California

You are going to have to speak with a real estate attorney. The real estate attorney is going to want to see your title report, or have a title search performed to determine whether the county has an easement granted to them by a prior owner. The easement will normally run with the land, meaning it is binding on subsequent owners, including you.

I generally agree with Mr. Roach's answer, but there are other possibilities here too. Easement law might cover the situation, but any attorney investigating your rights should also consider whether the county's rights stem from a provision in the Streets & Highways Code. I live out in the country, and my property line goes to the center of the county road, or to put it another way, half of the county road is on my property. Long ago, I learned that this is possible due to a code provision, and it is not an ordinary easement. Sorry, this is all I know about the subject, but something to keep in mind.