What can a surveyor do if a property corner cannot be located during a survey?

When a property corner cannot be located during a survey, referencing with a witness monument is a reliable method to ensure that property boundaries can still be determined. A witness monument is a physical marker that is placed in a location where it can be seen from the original corner, serving as a reference point. This is particularly useful in cases where the original corner has been lost or destroyed.

Using a witness monument allows surveyors to maintain the integrity of the property lines by providing a verifiable location that can be re-established in the future. It also helps in preventing disputes over boundaries, as the witness monument serves as evidence of where a surveyor believes the corner should be based on previous measurements and confirmations.

The other options, while they may seem viable, do not ensure accuracy and reliability in boundary determination similarly as a witness monument does. For instance, using GPS technology can provide useful data, but it may not replace lost physical corners in terms of traditional boundary determination. Marking an arbitrary location can lead to confusion and potential disputes, and leaving the corner unmarked would undermine the survey's purpose. Therefore, referencing a witness monument is the most appropriate and professional practice in this situation.