Three property line essentials for forestland ownership include having clearly marked property lines, a survey map, and being familiar with those lines. As a forester that is hired to work within the bounds of a property, it is essential that lines are easily identified. As a forester, I can't mark lines. I can only find them if they have already been marked.
Property ownership is defined by the deed. This deed may include the metes and bounds: a written description of the property lines. Metes and bounds will begin with a known reference point and describe the metes (distances) and bounds (direction) from that point, describing the polygon of the property.
Having a deed with metes and bounds doesn't mean that the lines are actually marked. A hired surveyor will reference (or create) the metes and bounds to mark property lines. In Vermont, forested property lines are marked by using a machete or cutting tool and cutting a slice of bark off a tree at about chest height and painting that tree wound, thus creating a blaze. If the line goes through a field property lines generally aren't marked. Within the forest, blazes are on the side of a tree that faces the line and if the line goes through a tree, that tree may have blazes on both sides of a tree.
Property corners are marked with monuments, pins or rods. I've seen cement columns, piles of stone, and large trees that are intended to demarcate a corner. Typically an iron pipe or rebar is used as a corner with a plastic cap that identifies the surveyor by name.
This photo shows a typical capped iron rebar identifying a corner with the red blazes in the background. Three blazes as shown here, typically identify a corner, with the blazes facing the corner pin. Notice the barbed wire fence that often accompanies a property line, but should not be considered the line.
Property lines, marked by surveyors require upkeep. The paint will fade and the wounds on the tree will change too. Most often they heal over, but they may also create larger wounds which obscure the fact that it is a mark. The trees may simply die.
Landowners may freshen the blazes by re-painting or re-cutting known blazes but they can't create new blazes. That is for a licensed surveyor. Flagging is also used as a way to orient to a property line and communicate the location of the line. but flagging will only last 1-2 years before it requires refreshing.
The survey map is the visual representation of the metes and bounds and can be recorded with the town clerk as a legal record of the property lines and potentially more importantly, the acreage.
Being familiar with your property lines is important. Being able to find them regularly and communicate them effectively is also important. Developing a search image for finding property lines takes experience. Trees re-heal, paint fades and each blaze will look a little different. Below is a few shots of different blazes from most clear to most obscured, but all still recognizable.
Knowing where the property lines are, rather than guessing, is extremely important. It is important to have clearly marked lines prior to engaging in forest land activity like logging or any land transactions. Additionally by having clearly marked property lines you are protected from your neighbor's activities and they're (or their contractor's) negligence.
If you don't know where your property lines are, the first step is go look. Reference your survey or visit your town clerk to find if your deed is accompanied by the metes and bounds. If after looking, you can't find your lines, a Forester with a better search image might be better equipped to find the line. Often however, a surveyor is still needed to find lost corner pins or remark or create a survey map.
Notes on trees along the property lines:
You and your neighbor share trees that the line goes through, each owning 50% of that tree or products of that tree. You are not allowed to deface a property line marker or cut a marked tree. You should however, think of blazes as locating a line rather than being the line. Because trees don't grow in a line, the blazes may be offset from the line creating the appearance that the line has a certain width. A line is a line but unmarked trees that you are unsure of which side of the line the tree is on, are best left untouched.