How do you determine property lines?
Have a surveyor do a stake survey to show the property lines. It
will cost a few hundred dollars in the city, or up to a few
thousand dollars for a rural property. The surveyor must usually
find the deeds that reference and define your property and those of
your neighbors and make a determination of where your property
lines are. Depending upon how your property is defined, your lines
may be very difficult to locate exactly, if not impossible (e.g.,
"from the large birch tree to the pile of stones", neither of which
can be found 50 years later). When neither you nor your neighbors
can find the lines, you can establish a "new" line by agreement and
record that with the deeds for future reference.
When attempting to locate lines for a new fence, some
jurisdictions require consultation with the official "fence viewer"
who will help establish the line, if there is a dispute.