The "Good Neighbor Fence Act" is the common name for California's Civil Code Section 841, which governs how neighbors must share the cost and responsibilities for fences on their shared property line.
You may find approximate locations of your property lines on city’s GIS Parcel Data Map or you may obtain a copy of the parcel map from the County Assessor’s Office website. However, the exact location of your property lines can only be verified by a licensed surveyor.
Prescriptive easements are often a point of contention between neighbors and can be difficult to resolve without legal assistance.
It's crucial to consult with a real estate attorney if you are dealing with a potential or existing prescriptive easement.